A block made of glass and a block made of wood have the same mass. Each block is pulled by a rope at constant speed the same distance along a horizontal steel surface. Would the same amount of work be required to pull the glass block as the wood block?A.Yes, because the masses of the blocks are the sameB.Yes, because the blocks are pulled along a horizontal surfaceC.No, because the coefficients of static friction for the block materials on steel are differentD.No, because the coefficients of kinetic friction for the block materials on steel are different
Question
A block made of glass and a block made of wood have the same mass. Each block is pulled by a rope at constant speed the same distance along a horizontal steel surface. Would the same amount of work be required to pull the glass block as the wood block?A.Yes, because the masses of the blocks are the sameB.Yes, because the blocks are pulled along a horizontal surfaceC.No, because the coefficients of static friction for the block materials on steel are differentD.No, because the coefficients of kinetic friction for the block materials on steel are different
Solution
The correct answer is D. No, because the coefficients of kinetic friction for the block materials on steel are different.
Here's why:
Work is defined as the force required to move an object a certain distance. In this case, the force required is the force to overcome friction.
Friction depends on two things: the normal force (which is the same for both blocks because they have the same mass and are on a horizontal surface) and the coefficient of friction. The coefficient of friction depends on the two materials that are in contact - in this case, the block material and steel.
Since glass and wood have different coefficients of friction with steel, the force required to move them (and therefore the work done) will be different.
So, even though the blocks have the same mass and are moved the same distance, the work done on each block is not the same because the force of friction acting on each block is different.
Similar Questions
Block 1 and Block 2 have the same mass, m, and are released from the top of two inclined planes of the same height making 30o and 60o angles with the horizontal directoin, respectively. If the coefficient of friction is the same in both cases, which of the blocks is going faster when it reaches the bottom of its respective incline? Block 1 is faster Block 2 is faster. More information is needed to know which block is faster. Both blocks have the same speed at the bottom.
A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of 60∘ by a force of 10 N parallel to the inclined surface as shown in figure. When the block is pushed up by 10 m along inclined surface, the work done against frictional force is : [g=10 m/s2]
Two blocks are arranged as below, connected together by rope and pulley with m1 = 3.50 kg and m2 = 7.00 kg. The coefficient of kinetic friction between all surfaces is 0.250. The top block is pulled to the right with a force F = 69.2 N. What is the acceleration of the top block?
. In addition to the final velocity of the block, which of the following information would students need to test the hypothesis that the work done by the net force on the block is equal to the change in kinetic energy of the block as the block moves from
A block of mass m = 2.50 kg is pushed a distance d = 2.20 m along a frictionless,horizontal table by a constant applied force of magnitude F = 16.0 N directed at anangle θ = 25.0° below the horizontal. Determine the work done on the block by:(a) the applied force.(b) the normal force exerted by the table.(c) the gravitational force.(d) the net force on the block.
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.