A box is given a push across a horizontal surface. The box has a mass m, the push gives it an initial speed of 2.40 m/s, and the coefficient of kinetic friction between the box and the surface is 0.140. (a) Use energy considerations to find the distance (in m) the box moves before it stops. m (b) What If? Determine the stopping distance (in m) for the box if its initial speed is doubled to 4.80 m/s.

A 7.80-g bullet moving at 600 m/s penetrates a tree trunk to a depth of 4.80 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.

A child of mass m = 16 kg slides down a slide of height h = 2.7 m without friction. Let gravitational potential energy be zero at ground level. a)Write an expression for the child's total mechanical energy, E, at the top of the slide, in terms of the variables in the problem and the acceleration due to gravity g.  b)Calculate the change in the child's potential energy, ΔU in joules, from the top to the bottom of the slide at ground level (i.e. ΔU = Uground - Utop).  c)What is the child's final speed, vf in m/s?

A center throws a basketball m = 1 kg straight up with an initial speed of vo = 9.5 m's. He releases the ball at shoulder | height ho = 1.9 m. Let gravitational potential energy be zero at ground level. Give the total mechanical energy of the ball E in terms of maximum height h it reaches, the mass m, and the gravitational acceleration g. E= What is the height, hm in meters? 9 HOME

A 5.80-kg block is set into motion up an inclined plane with an initial speed of v₁ = 8.20 m/s (see figure below). The block comes to rest after traveling d = 3.00 m along the plane, which is inclined at an angle of 0 = to the horizontal. V. (a) For this motion, determine the change in the block's kinetic energy. (b) For this motion, determine the change in potential energy of the block-Earth system. (c) Determine the friction force exerted on the block (assumed to be constant). N (d) What is the coefficient of kinetic friction?

A crate is given a push across a horizontal surface. The crate has a mass m, the push gives it an initial speed of 3.60 m/s, and the coefficient of kinetic friction between the crate and the surface is 0.130. (a) Use energy considerations to find the distance (in m) the crate moves before it stops.   ____m   (b) What If? Determine the stopping distance (in m) for the crate if its initial speed is doubled to 7.20m/s.   ____m

A 7.80-g bullet moving at 470 m/s penetrates a tree trunk to a depth of 5.60 cm.(a) Use work and energy considerations to find the average frictional force that stops the bullet.N (b) Assuming the friction force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.s

A 7.80-g bullet moving at 560 m/s penetrates a tree trunk to a depth of 4.80 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 640 m/s penetrates a tree trunk to a depth of 6.10 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 sled is given a push across a horizontal surface. The sled has a mass m, the push gives it an initial speed of 3.40 m/s, and the coefficient of kinetic friction between the sled and the surface is 0.150. (a) Use energy considerations to find the distance (in m) the sled moves before it stops. m (b) What If? Determine the stopping distance (in m) for the sled if its initial speed is doubled to 6.80 m/s. m