A 7.80-g bullet moving at 520 m/s penetrates a tree trunk to a depth of 5.30 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.

A 36.0 kg box initially at rest is pushed 5.45 m along a rough, horizontal floor with a constant applied horizontal force of 150 N. If the coefficient of friction between box and floor is 0.300, find the following. (a) the work done by the applied force (b) the increase in internal energy in the box-floor system due to friction (c) the work done by the normal force (d) the work done by the gravitational force (e) the change in kinetic energy of the box (f) the final speed of the box m/s

A 3.7-kg block is pushed 2.3 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of 0 = 30° with the horizontal, as shown in the figure below. If the coefficient of kinetic friction between block and wall is 0.30, determine the following. (a) the work done by F (b) the work done by the force of gravity (c) the work done by the normal force between block and wall (d) By how much does the gravitational potential energy increase during the block's motion?

4. A 4.7 kg block is pushed 3.1 m up a vertical wall with constant speed by a constant force of magnitude Fapplied at an angle 8=35° with the horizontal, as shown in the Figure. If the coefficient of kinetic friction between block and wall is 0.23, determine a) The work done by F, b) the work done by the force of gravity, c) the work done by the normal force between block and wall. d) By how much does the gravitational potential energy increase during the block's motion? F

A 3.7-kg block is pushed 3.3 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of 0 = 30° with the horizontal, as shown in the figure below. If the coefficient of kinetic friction between block and wall is 0.30, determine the following. (a) the work done by F (b) the work done by the force of gravity (c) the work done by the normal force between block and wall (d) By how much does the gravitational potential energy increase during the block's motion?

A 7.80 g bullet is initially moving at 660 m/s just before it penetrates a block of wood to a depth of 4.40 cm.   (a) What is the magnitude of the average frictional force (in N) that is exerted on the bullet while it is moving through the block of wood? Use work and energy considerations to obtain your answer. _______________N   (b) Assuming the frictional force is constant, how much time (in s) elapses between the moment the bullet enters the block of wood and the moment it stops moving? _______________s

A box slides down a plank of length d that makes an angle of θ with the horizontal as shown. μk is the kinetic coefficient of friction and μs is the static coefficient of friction. a) Enter an expression for the minimum angle θ (in degrees) the box will begin to slide.  b) Enter an expression for the nonconservative work done by kinetic friction as the block slides down the plank. Assume the box starts from rest and θ is large enough that it will move down the plank.

ASK YOU A 7.80 g bullet is initially moving at 620 m/s just before it penetrates a block of wood to a depth of 5.80 cm. (a) What is the maanitude of the average frictional force (in N) that is exerted on the bullet while it is moving through the block of wood? Use work and energy considerations to obtain your answer. (b) Assuming the frictional force is constant, how much time (in s) elapses between the moment the bullet enters the block of wood and the moment it stops moving?

A 7.80-g bullet moving at 560 m/s penetrates a tree trunk to a depth of 5.80 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.

A 7.80-g bullet moving at 690 m/s penetrates a tree trunk to a depth of 5.10 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet.N(b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.s