On an essentially frictionless, horizontal ice rink, a skater moving at 3.0 m/s encounters a rough patch that reduces her speed to 1.65 m/s due to a friction force that is 25% of her weight. Use the work–energy theorem to find the length of this rough patch.

A 7.80-g bullet moving at 650 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. (Enter the magnitude.) 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 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.

On an essentially frictionless, horizontal ice rink, a skater moving at v = 3.0 m/s encounters a rough patch that reduces her speed to 45% due to a friction force that is 25% of her weight (w). Use the work-energy theorem to find the length of this rough path.Express first your answer in terms of any or all of the variables v, w, and g (acceleration due togravity), and then its numerical value

A bicyclist starting from rest applies a force of F = 239 N to ride his bicycle across flat ground for a distance of d = 210 m before encountering a hill making an angle of θ = 17 degrees with respect to the horizontal. The bicycle and rider have a mass of m = 120 kg combined. In this problem, you can ignore air resistance and other losses due to friction.How much work, W in joules, did the rider do before reaching the hill? What is the bicycle's speed, v in m/s, just before the hill? If the cyclist starts coasting at the bottom of the hill, what distance, di in meters, does the bike travel up the incline?

A 7.80-g bullet moving at 570 m/s penetrates a tree trunk to a depth of 4.40 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 skier moving at 5.00 m/s encounters a long, rough horizontal patch of snow having a coefficient of kinetic friction of 0.220 with her skis. How far does she travel on this patch before stopping? Solve it using the work-energy theorem.

A bicyclist rides 1.90 km due east, while the resistive force from the air has a magnitude of 7.13 N and points due west. The rider then turns around and rides 1.90 km due west, back to her starting point. The resistive force from the air on the return trip has a magnitude of 7.13 N and points due east. Find the work done by the resistive force during the round trip. Number Units

You may have noticed runaway truck lanes while driving in the mountains. These gravel-filled lanes are designed to stop trucks that have lost their brakes on mountain grades. Typically, such a lane is horizontal (if possible) and about 40.0 m long. Think of the ground as exerting a frictional drag force on the truck. A truck enters a typical runaway lane with a speed of 50.5 mph (22.6 m/s). Use the work-energy theorem to find the minimum coefficient of kinetic friction between the truck and the lane to be able to stop the truck.

You may have noticed runaway truck lanes while driving in the mountains. These gravel-filled lanes are designed to stop trucks that have lost their brakes on mountain grades. Typically, such a lane is horizontal (if possible) and about 40.0 m long. Think of the ground as exerting a frictional drag force on the truck. A truck enters a typical runaway lane with a speed of 59.0 mph ( 26.4 m/s ). Use the work-energy theorem to find the minimum coefficient of kinetic friction between the truck and the lane to be able to stop the truck.