A net external force is applied to a 7.13-kg object that is initially at rest. The net force component along the displacement of the object varies with the magnitude of the displacement as shown in the drawing. (a) How much work is done by the net force? (b) What is the speed of the object at s = 20.0 m?

A child on a sled is initially at rest on an icy horizontal surface. The sled is pushed until it reaches a final velocity of 6.05 m/s in a distance of 15.6 m. The coefficient of friction between the ice and runners of the sled is 0.200, and the weight of the child and the sled is 375 N. Find the work done by the force pushing the sled.

A force given by (6i – 3j) N acts on an object experiencing a displacement given by (3i – j) m.  Determine the work done by the force.

A helicopter lifts a 65 kg astronaut 18 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g/10. (a) How much work is done on the astronaut by the force from the helicopter? (b) How much work is done on the astronaut by her weight? (c) What is the kinetic energy? (d) What is the speed of the astronaut just before she reaches the helicopter? m/s

A block of mass ?=0.350kg is released from rest, from a curved ramp of height h= 42.0 cm (point A in the figure). The block slides down frictionless to the bottom of the ramp to point B. a) What is work done by gravity when the block moves from A to B? b) What is the speed of the block at the bottom of the ramps (point B in the figure)? c) The box continuesto slide frictionless and compress a spring a distance Δ?=8.20cm until it stops at point C. What is the spring constant k of the spring? d)What is the elastic potential energy stored in the spring when the block is at point C?

A 4.5-kg block slides down a frictionless incline making an angle of 55.0° with the horizontal. (a) What is the total work done on the block when the block slides 1.4 m (measured along the incline)? (b) What is the speed of the block after it has slid 1.2 m if it starts from rest? m/s (c) What is its speed after 1.2 m if it starts with an initial speed of 1.6 m/s? m/s You can use the definition of work as the scalar product of a constant force and displacement to find the work done by each force acting on the block. Then use the work- kinetic energy theorem the find the speed of the block at any given location and for any initial kinetic energy it may have.

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 0.32-kg particle has a speed of 5.0 m/s at point A and kinetic energy of 8.1 J at point B. (a) What is its kinetic energy at A? (b) What is its speed at point B? m/s (c) What is the total work done on the particle as it moves from A to B?

On a horizontal surface, an object slides from point P to point Q along a straight line, then slides back from Q to P along a semicircle. If P and Q are a distance L apart, how much work did the force of kinetic friction do during the entire process? The magnitude of fk is fk.

A 0.59-kg particle has a speed of 5.0 m/s at point A and kinetic energy of 8.5 J at point B. (a) What is its kinetic energy at A? J(b) What is its speed at point B? m/s(c) What is the total work done on the particle as it moves from A to B? J