Since the cord does not slip on the pulley, the tangential acceleration of a point on the run of the pulley must be the same as the acceleration of the blocks, so ( = a/R = 0. Prior studies seemed to say no. Apparatus: A wooden block, an inclined plane with pulley, cord, weights, a protractor, a balance, and. Dynamics – Freefall, Apparent Weight, and Friction (Honors) PURPOSE To investigate the vector nature of forces. 05 cm, which turns with negligible friction. Also A has no friction, so is not resisting the vertical acceleration. Find the minimum angle so that both blocks move with the same acceleration. The system is released from rest. Examining the problem object by object we see that the spring stretches, so there is an increase in spring potential energy. Consider a system of two blocks pushed by a certain force Fagainst a vertical wall, as shown below. A 600-N block is lifted by the friction-free pulley system shown. And that's trick. The friction is simply N = 0. [1997-5 marks]. Find the acceleration and the tension of the string. There are two bodies in the system, and we draw free-body diagrams of each of them. of friction at the contact surface between them (but no friction with table that M 2 rests on). What is the tension in the string supporting body 1? (d) Find the magnitude and direction of the acceleration of body 2, of pulley A, of body 3, and the tension in the string supporting pulley A. Single Pulley Systems No Friction is present. The truck has no acceleration so there is no net force and so there must be a force going up the slope, which of course is from static friction, denoted by Fstat. A bag of cement whose weight is F g hangs in equilibrium from three wires shown in Figure P5. Physics 100A Homework 5 – Chapter 6. a) (10 points) In the figure, superimpose complete free-body diagrams for each of the blocks. A curve with an increasing slope. Of course, friction must be brought into the energy approach as well. Students will calculate a theoretical acceleration value using their derived equation, and then compare their. But in real life, there will be some friction which acts to slow the cart down. Use g = 10. How come no one notices that you pushed the earth? 3. a) The input force is in a different direction than the output force. However, friction reduces the acceleration and the effect is greater for a trolley with a small mass. Let the mass of the pulley be 1-kg and approximate the pulley as a solid disk of radius r=0. Generally pulley systems on our physics papers are very idealized frictionless pulleys which seemed without mass. Friction is opposition to motion, so if nothing is trying to move there will be no friction. The system of blocks A and B and two pulleys C and D is assembled as shown in the figure. 6 rad 13) Angular momentum cannot be conserved if A) there is a net force on the system. The supermassive black holes originally in the nuclei of two merging galaxies will form a binary in the remnant core. So, the easy way to do this, the way to get the magnitude of the acceleration of the objects in your system, that is to say, if I wanna know the magnitude at which this five kilogram box accelerates, or that this three kilogram box accelerates, all I need to do is take the net external force that tries to make my system go, and then I divide by. what are the acceleration of teh two masses with respect to the ground?. 0 kg mass is attached to a 10. Explain why. One of the blocks is on a table with friction and the other hangs off the end of the table. We found that the block accelerates down the slope with uniform acceleration , where is the angle subtended by the incline with the horizontal. Example 3) Wedge and mass system. The pulleys are ideal, and the coefficient of kinetic friction between block B and the tabletop is 0. The normal force N 1 must therefore be equal to m 1 g cos([theta]). 1 The concepts of force and mass FORCE A force is a push or pull upon an object resulting from the object's interaction with another object. You will calculate the acceleration in three studies. If they have the same sign then the friction won't hold the system in place. 2 Mass m 1 on a frictionless horizontal table is connected to mass m 2 through a massless pulley P 1 and a massless fixed pulley P 2 as shown in Figure P5. b) Find the magnitude of the tension of the string between m 1 and m2. Problem: Two masses on a pulley. Find the acceleration. " With such a question, you don't even need to know the correct formula, but you do need to understand how the pulley system works. Two blocks, m 1 = 6. thanks in advance. It shows that the acceleration is directly proportional to the mass. However, T 0 can be thought of as the tension required to cause the cart to move with zero acceleration, that is, the tension required to overcome kinetic friction. For a long time, then, theorists believed that the soliton moved through its cloudy quantum surroundings essentially untouched. This is a classic introductory physics problem. notebook 3 October 17, 2011 5. To calculate , the coefficient of friction, tilt the ramp until the block travels at a constant velocity after you tap it to get it moving. Purpose The purpose of this experiment is to demonstrate how imperfections in the experimental apparatus can play a large role in the final results. For an ideal pulley/peg the tension in the string is the same on both sides. (a) If the system is released from rest, what will its acceleration be?. figure below. Of course, friction must be brought into the energy approach as well. Systems of Blocks and Pulleys 1. machine that experiences no friction so work in equals work out: real machine: a machine that experiences friction so work out is always less than work in: pulley: an object with a groove like wheel, with a rope or chain running through the groove; changes the direction of the input force: lever. Light pulley ( no mass ( right hand side of F = ma equation is 0. (b) If there is no mechanical advantage to class 3 levers, why are they considered useful? 4. A bag of cement whose weight is F g hangs in equilibrium from three wires shown in Figure P5. 00 kg block therefore accelerates to the right and the suspended block accelerates downward. μ = mechanical efficiency of the system (equal to one for an ideal friction-less system, a fraction less than one for real-world systems with energy losses due to friction) n = number of ropes between the sets of pulleys. A car of mass 600 kg towes a trailer of mass 250 kg in a straight line using a rigid towe-bar. The rope and the pulleys are massless and there is no friction. This establishes the size of the air friction force at 6. Neglecting friction in and the mass of the pulleys, and assuming that the whole system is initially at rest, determine the acceleration of block A. 500-kg cart to accelerate it across a low-friction track. 1b Ans co 20 rad/s o. 0 m/s2, what is the force of friction on the crate? (c) What is the maximum acceleration the truck can have without the crate starting to slide? (a) Since the truck is not accelerating, there is no external force on the crate in the. = 0 Continued In the collision of two isolated objects, the only forces are between the two objects—these are called internal forces. The system remains at rest this is what would happen if there were no. The Pulley System makes use of a disk-shaped block that a rope wraps around to create a simple machine. The coefficient of friction between block A and the wedge is 2/3 and that between block B and the wedge is 1/3. However, friction will be present when motion is attempted, even if the object is not yet moving. The acceleration of show more A 14 kg mass on a frictionless inclined surface is connected to a 1. • To practice the use free-body diagrams (FBDs). There are two bodies in the system, and we draw free-body diagrams of each of them. [Assumptions: no friction, the mass of the pulley and string are negligible. Find the acceleration of the system. Since they are attached, the blocks will be moving with the same velocity and acceleration. 00 kg and can slide along a rough plane inclined 30. Mass has nothing to do with size! Force is measured from the acceleration it produces. We started with no mass on the wooden block, then we added a 50 g mass to the block for each successive trial. The pulley is massless and firctionless, and the connecting string is massless and does not stretch. We consider the cord and pulley to have no mass and no friction. LoRusso Example 3: a) Find the acceleration of the system (assume no friction) b) Find the tension in the string. There is no friction between block A and the surface. The other end of the rope is held by the person. 3 above and the tension in each string if there is no friction in the system. Find the angular acceleration of the cylinder. friction, the acceleration is measured to be only a = 3. Additional Exercises on Chapter 6 Figure 6-8 1)Two masses are connected by a string which goes over an ideal pulley as shown in Figure 6-8. What I have now is a pulley that allows the rope to pass through freely, with no friction or resistance. Example: A block of mass m1 on a rough horizontal surface is pulled with a force FA at an angle θ to the horizontal. If pulley is light and frictionless then tension in the string on both sides is same. Video static friction explains what is friction, types of frictional forces, what is static friction? examples and numericals of static friction & more BUY COURSES +91 7888272625. 20, calculate the acceleration of each body and the tension T in the cable. Since a tension acts upward on the hanging mass, the mass is not in free fall and the acceleration is less than g. This will provide a way to roughly compensate for the (small) effect of the pulley. Another way to justify it is to treat the block + pulley as a single system, and the gravity force on the system is the force vector shown. Find the acceleration and tension forces involved. Buy Surflex High Torque Friction Plates at Demon Tweeks. Two blocks, m 1 = 6. The direction of force F rightward, the direction of friction force leftward (the direction of friction force is opposite with the direction of object’s motion). Solution: Denote m 1 = 4 kg, m 2 = 2 kg, gravity acceleration g = 9. Pulley – 1. (a) What is the acceleration of the lighter block? (b) Suppose that the heavier block is removed, and a downward force of 600 N is provided by someone pulling on the rope, as part b of the drawing shows. Two blocks are hung from the ends of a rope that goes over a pulley. (c) (10 oints)p Find an expression for the acceleration of mass M 1. A crate of mass 100 kg is at rest on a horizontal floor. Mechanical energy is not conserved. Two masses, m 1 and m 2 (m 1 < m 2) are connected to the rope over the pulley. friction between the sled and the surface is 0. 4 m/s2 D) 9. Assume that friction is negligible, and. Consider the simplest form of Atwood machine, with no friction and a massless pulley. Sph4u Force, Pulleys and Gravity Mr. Regular Atwood (Pulley with two masses) Two masses, string has negligible mass Pulley negligible mass, no friction. B) When two objects are in contact with no relative motion, the magnitude of the frictional force may be either less or equal to. So, the easy way to do this, the way to get the magnitude of the acceleration of the objects in your system, that is to say, if I wanna know the magnitude at which this five kilogram box accelerates, or that this three kilogram box accelerates, all I need to do is take the net external force that tries to make my system go, and then I divide by. Pulleys are useful for us to lift objects as they reduce the amount of force we need to exert. The head (or ball) of the patient’s femur fits into a cup that has a hard plastic-like inner lining. Direction of force that a rope exerts on an object? Role of fixed pulleys (frictionless, massless). Contact Forces Introduced. 6 m/s2, the force of the spring has a magnitude of: A) an undetermined amount B) 2. Kinetic friction, or the friction of an object in motion, is equal to the coefficient of friction multiplied by the normal force of an object. Assume the strings and pulleys have negligible mass. The coefficient of friction is 0. 00 ft/s2 but is still moving upward?. 0 kg package from an initial position of 1 jˆ at t = 0 to a final position of 2 jˆˆ at t = 4. The study of the causes of motion is called dynamics, or mechanics. pulley is modeled as massless and frictionless, the tension in the string on both sides of the pulley is the same. We started with no mass on the wooden block, then we added a 50 g mass to the block for each successive trial. The system is released from rest. Nothing is pushing them to the outside; acceleration is toward the middle. Bearing friction can be neglected. The only force on it is , and it has the acceleration found above. which is distributed uniformly over its disk-like shape. that would make the angular acceleration of the system equal to zero. To develop a clear concept of the idea of apparent weight. In the figure below, the pulleys are light and frictionless, and the coefficients of friction between the blocks and the surfaces are μ. Video static friction explains what is friction, types of frictional forces, what is static friction? examples and numericals of static friction & more BUY COURSES +91 7888272625. Eliminate the common acceleration and solve for the tension in the strings. (c) Indicate whether the magnitude of the acceleration of block 2 is now larger, smaller, or the same as in the original two-block system. In this applet, a zero acceleration means no motion; therefore, try to keep the acceleration nearly zero, under 0. This will provide a way to roughly compensate for the (small) effect of the pulley. Determine the acceleration of the blocks. •Force of friction: know distinction between static (no acceleration) and kinetic (there is motion relative to the surface) •Circular motion: if moving along a circle sum of forces along the radial direction MUST add to mv 2/r F x ma x; F y ma y; F z ma z For constant coordinate system r F on A by B r F on B by A. In the drawing, the rope and the pulleys are massless, and there is no friction. Physics 100A Homework 5 - Chapter 6. Taking downward as the positive direction for the hanging mass, the acceleration will be. Only the force acting on the pulley changes. How many strands of rope support the 600-N weight? b. 2 N T A F g F N +y +x T B F g +y 9 1. A simple gear train is composed of three gears. Find many great new & used options and get the best deals for Petzl Freino Carabiner With Friction Spur Olive/red M42 at the best online prices at eBay! Free shipping for many products!. ANSWER: The reason all objects experience the same acceleration in a gravitational field is that the force is proportional to the mass (F=mg) and acceleration is inversely proportional to the mass (a=F/m), so mass cancels out. Solution: First need to check if blocks moveAssume the blocks are at rest and calculated the needed friction. as one system. Find an expression for the acceleration a of the red block after it is released. Mechanical advantage in the ideal case is 2. asked by Anonymous on April 10, 2013; Physics. This will be important when we take friction into account. platform can calculate the acceleration of the system by measuring the the angle (θ) of the ball. Pulley has an axle around which it rotates and a string passes over the pulley. They are (1) the lever (2) the pulley system (i. kinetic friction between the incline and the block? 3). friction between the disks is Pk = 0. The coe cient of static friction between the book and frictionless pulley to a 5. In the past, we assumed that the cart rolled and the pulley rotated without friction. Using Newton's Second law,Mg - T = Ma and T -mg = ma, T is the tension here, M is mass of heavier block and m of the lighter block. * "If there is no friction, is there a formula that tells how fast I would go down the zipline?". Thus the system is not in free fall. Best Answer: It would be very helpful to tell us if there is friction between the 3. The truck has no acceleration so there is no net force and so there must be a force going up the slope, which of course is from static friction, denoted by Fstat. a) The input force is in a different direction than the output force. In this applet, a zero acceleration means no motion ; therefore , try to keep the acceleration nearly zero, under 0. You can assume that the rope is massless and inextensible, and that the pulley is frictionless. much simpler pulley system, but now there is no friction between m1 and the block, but some friction between m2 and the block. If there WAS friction it would've been different, since friction is dependant on the mass and operates as a repellent force (opposing the movement). The pulley is fixed, and the string can slide over the pulley. Block, Tackle or Pulley Calculator. Assume there is NO friction. (a) What is the magnitude of the block’s acceleration? (b) The force magnitude F is slowly increased. Now that the acceleration has been found from Equation 5, its value can be substituted into Equation 4 in order to determine the tension. Note: You will receive no credit for late submissions. the tension in the rope _____ 3. Try to keep the system as light as possible. Static Friction Calculator: Make use of the given online static friction coefficient calculator to calculate the static friction, its coefficient, and normal force. Pulleys A little force goes a long way, but there's no free lunch! A pulley is a simple machine that allows you to lift a large weight using a small force. [1997-5 marks]. According to Newton’s 2nd Law, the acceleration of a system is _____ proportional to the total mass of the system and _____ proportional to the net force acting on the system. If the system is set in motion with m1 moving to the right, then what will be the magnitude of the system's acceleration? Consider the pulley to be massless and frictionless. Using Newton's Second law,Mg - T = Ma and T -mg = ma, T is the tension here, M is mass of heavier block and m of the lighter block. The rope and the pulleys are massless and there is no friction. In the drawing, the rope and the pulleys are massless, and there is no friction. The friction coeﬃcient being µ. Force is a vector quantity. Determine the kinetic energy of the system. View our entire inventory of New or Used Yamaha Motorcycles. No products in the cart. Remember that inertia must be overcome to start an object moving. pulley is modeled as massless and frictionless, the tension in the string on both sides of the pulley is the same. / 50 for this page ½M M P Rough. The cart accelerates to the right when the cylinder. n = m 2 g cos. What maximum height does the lighter object reach after the system is released? [Hint: First determine the acceleration of the lighter mass and then its velocity at the moment the heavier hits the ground. What is the acceleration of the system? How far will it move in 2. What is the acceleration of the 10. Newton's third law says that for every action there is an equal and opposite reaction, so the total force of the system F will equal the force in the rope or T (tension) + G (force of gravity) pulling at the load. ” With such a question, you don’t even need to know the correct formula, but you do need to understand how the pulley system works. Remember that inertia must be overcome to start an object moving. Thus the system is not in free fall. c Because the pulley is smooth, there is no friction, so the magnitude of acceleration of P = the The acceleration of the system is 0. The coefficient of friction is 0. Apparatus: A wooden block, an inclined plane with pulley, cord, weights, a protractor, a balance, and. To learn more, read your instructor's Grading Policy Acceleration of a Pulley Description: A block of mass m hangs from a string wrapped around a cylinder that also has mass m. m F a NET G G = FNET ma G G = m F a NET x x =, m F a NET y y Vectors! =, Mass – measure of inertia (kg). 5 kg, R = 0. Acceleration (a) = 3 m/s 2. 09kg and the smaller block has a mass of 4. The relation between force and acceleration was given by Isaac Newton in his three laws of motion, which form the. Assign mass ( M) to the pulley and treat it as a rotating disc with radius (R). The pulleys are ideal, and the coefficient of kinetic friction between block B and the tabletop is 0. the tension in the rope _____ 3. Find many great new & used options and get the best deals for Petzl Freino Carabiner With Friction Spur Olive/red M42 at the best online prices at eBay! Free shipping for many products!. Sph4u Force, Pulleys and Gravity Mr. The friction force depends on the mass of an object plus the coefficient of sliding friction between the object and the surface on which it slides. Two blocks are connected by a rope, through a pulley as shown in this figure. 1 m and mass M=3 kg. However, the tension in both sections of rope is equal, even if both ends of the rope are being pulled by forces of different magnitudes. Spring, string, pulley are massless. 01 ×104 N so that is the magnitude of the friction force. Used to lift parallel loads, both lengths have the same amount of tension. Consider the system as shown in the figure with m1 = 20 kg, m2 = 12. The inclined plane is frictionless and at angle 30°. What is the value of the acceleration ? A. Ignore the mass of the pulley. 00 kg and on the other side is a mass of 1. There are two bodies in the system, and we draw free-body diagrams of each of them. If the system is accelerating with g 6 m s2 acceleration, calculate the friction force in between the table and the box. Yamaha ATVs For Sale: 1176 ATVs Near You - Find Used Yamaha ATVs on ATV Trader. Now that the acceleration has been found from Equation 5, its value can be substituted into Equation 4 in order to determine the tension. 4kg mass and the surface; but since you gave us the answer, I can determine that the problem means to say there is no friction between these surfaces. Assuming no friction, calculate the speed at points 2, 3, and 4. EVALUATE: (c) With friction on both halves, all the initial potential energy gets converted back to potential energy. This video is useful for students. A lightweight string connects a 2. 0 kg mass hangs off the edge of the table. The rope and the pulleys are massless and there is no friction. In the system shown in the figure, friction and the mass of the pulley are both negligible. (b) What is the tension when the elevator is decelerating at the rate of 4. 8 A gear reduction system consists of three gears A, B, and C. Newton's third law says that for every action there is an equal and opposite reaction, so the total force of the system F will equal the force in the rope or T (tension) + G (force of gravity) pulling at the load. 0∘ and a coefficient of kinetic friction between block 2 and the plane of μ = 0. What I did was I used two different weights and found the acceleration of the lighter weight going up the pulley. Two masses of 80 kg and 140 kg hang from a rope that runs over a pulley. 72 N, then what is the cart's acceleration?. Assuming no axle friction, determine the angular acceleration of the pulley and the acceleration of each block. When the hanging mass is released, it falls down and the cart accelerates along the frictionless track. gcosθm g F. Only the force acting on the pulley changes. Now that the acceleration has been found from Equation 5, its value can be substituted into Equation 4 in order to determine the tension. Consider the system as shown in the figure with m1 = 20 kg, m2 = 12. Physics problems: dynamics. Assume the rope is massless, there is no slipping of the rope on the pulley, and there is no friction between m1 and the incline. A fixed (attached to a non-moving object) pulley changes the direction but not magnitude. 0 N and M= 5. Two blocks are connected by a rope, through a pulley as shown in this figure. Note: You will receive no credit for late submissions. ” With such a question, you don’t even need to know the correct formula, but you do need to understand how the pulley system works. 8 A gear reduction system consists of three gears A, B, and C. NB: For this problem, a coordinate system of right for A, down for m and clockwise for the pulley is adopted to be positive. Solution 8. Taking downward as the positive direction for the hanging mass, the acceleration will be. 10 hours ago · There is no feel of sluggishness or excessive valve-train noise. Find the acceleration of the remaining block. All surfaces, pulley, and wheels are frictionless. mass m, the acceleration a that results is directly proportional to the net force and has a magnitude that is inversely proportional to the mass. 00 kg, as shown below. hi, im stuck in a part of a project, im not the strongest in physics and here im trying to build a system but im struggling to calculate the torque needed to rotate a load via belt attached to a pulley and that pulley attched to a motor. Direction of force that a rope exerts on an object? Role of fixed pulleys (frictionless, massless). Find the acceleration of m2 if m1 = 300 g, m2 = 500 g, and F = 1. n 'ift B 301b. The direction of force F rightward, the direction of friction force leftward (the direction of friction force is opposite with the direction of object’s motion). 0 kg block and a 3. The box starts from rest. Timings can easily be converted into distances, speeds, and accelerations. 0∘ and a coefficient of kinetic friction between block 2 and the plane of μ = 0. This course by AM Sir revolves around the concept building of Friction. Pulley system on a double inclined plane. , both move with same velocity) –Cable is in tension but does not stretch • Draw FBDs and write equations of motion • If pulley is not ideal, discuss modeling modifications chp3 24. Apparatus: A wooden block, an inclined plane with pulley, cord, weights, a protractor, a balance, and. 500kg , is connected over an ideal (massless and frictionless) pulley to block 2, of mass m2, as shown. (a) What is the linear acceleration of the falling bucket?(b) How far does it fall?(c)What is the angular. 5 kg, R = 0. All the pulleys and strings are considered massless and there is no friction in the pulleys Note that top pulley doesn’t move. The product of mass times gravitational acceleration, mg, is known as weight, which is just another kind of force. Example: A block of mass m1 on a rough horizontal surface is pulled with a force FA at an angle θ to the horizontal. This is a model. 4kg mass and the surface; but since you gave us the answer, I can determine that the problem means to say there is no friction between these surfaces. 4U Pulleys and Ramps Worksheet. If the pulley is massless and the surface is frictionless, the magnitude of the acceleration of the 3. Now that the acceleration has been found from Equation 5, its value can be substituted into Equation 4 in order to determine the tension. 2, and the rotational kinetic energy of the pulley is 1 2 I!2 = 1 2 µ 1 2 MR2 ¶‡ v R ·2 = 1 4 Mv2: Some energy was also lost to friction, so we must take that into account. 0 kg F a m = = = This is the acceleration of each piece of the system. (D) The ball will have an upward acceleration equal to g at its lowermost position. The convenient thing to do for this problem is to let friction be the negative one. There is no. - There is no acceleration in both x and y because there is no movement in either of the component. If the string slides over the pulley that is not a source of 'error'. Suspend the pulley from a ring stand or other support. 0 kg mass hangs off the edge of the table. How to find the frictional force on a pulley? We are doing a Atwood's Machine lab and our teacher asked us to find the kinetic friction force due to the pulley. and is the force that the axle exerts on the pulley. Without actually going back and doing it, is there a value you can provide so that I can get a theoretical value? 2- Which equation is which? What is the primary equation and which one is the theoretical?. The coefficient of friction between the block and the table is \mu= The pulley is frictionless. Because of the very low friction of the glider's wheels and of the pulley, any weight hung on the string resulted in a horizontal force pulling the glider along the track. For the vertical block, The tension in the string is T = m2 x (g-a) where m2 is the mass hanging on the chord, g is the acceleration due to gravity, and a is the acceleration of the system. There is no friction anywhere. The efficiency of a single movable pulley system is not 100% this is because. What is the maximum acceleration the truck can have without the crate slipping out the back? l Solving: v Visualize the problem, Draw a picture if necessary v Identify the system and make a Free Body Diagram. This is generally a common consideration for pulley tension problems. time graph look like. 2 N T A F g F N +y +x T B F g +y 9 1. Note: You will receive no credit for late submissions. This fixes the kinetic friction force. [1997-5 marks]. Test tube holder. “But weirdly, reversing time does not change the direction of acceleration, which the universe does care about. A mass and pulley problem? In the drawing, the rope and the pulleys are massless, and there is no friction. One axis must be in the direction of the acceleration you are trying to find. (m1 – m2)g d. Subtract this force from the applied force to find the acceleration of the object. (a) What is the force of friction acting on the crate? (b) If the truck speeds up with an acceleration of 1. According to Newton's first law, if an object is in static equilibrium, the net force on the object must be zero. and Friction The Atwood's Machine is used below to help in understanding how Newton's 2nd law applies to a system of two connected masses. A hanging mass spins a pulley. The study of the causes of motion is called dynamics, or mechanics. block and tackle) (3) the wheel and axle (4) the inclined plane (5. 600 m and an axle (no friction), starts from rest and speeds up uniformly as a 2. • Assume that the pulley is ideal –No mass and no friction –No slippage between cable and surface of cylinder (i. (a) Draw and label a free-body diagram for the sled-dog system as it is pulled along the surface. Linearizing the equation ( ) ( ). pulley is modeled as massless and frictionless, the tension in the string on both sides of the pulley is the same. The friction parameters used in the simulation are summarized in Table 2. 0 kg block is: (Ans: 2.