A 0.400-kg particle has a speed of 1.90 m/s at point circled A and kinetic energy of 7.10 J at point circled B. (a) What is its kinetic energy at ? J (b) What is its speed at ? m/s (c) What is the net work done on the particle by external forces as it moves from to?

At the instant it leaves the player’s hand after a jump shot, a0.62-kg basketball is traveling 8.4 m>s. When it passes through thehoop its speed is 6.8 m/s. (a) How much work has gravity done onthe ball? (b) What is the vertical component of the ball’s displacement? (c) If the magnitude of the total displacement of the ball is4.6 m, what is the angle between the displacement vector and thegravitational force?

A 70.00 kg jumper leaves the ground with a vertical velocity of 5 m/s. b.) What is his max potential energy during this jump?

(a) What force must be supplied by an elevator cable to produce an acceleration of 0.800 m/s2against a 200-N frictional force, if the mass of the loaded elevator is 1500 kg? (b) How much work is done by the cable in lifting the elevator 20.0 m? (c) What is the final speed of the elevator if it starts from rest? (d) How much work went into thermal energy?

A 6.5 g marble is fired vertically upward using a spring gun. The spring must be compressed 9.1 cm if the marble is to just reach a target 25 m above the marble's position on the compressed spring. (a) What is the change AUg in the gravitational potential energy of the marble-Earth system during the 25 m ascent? (b) What is the change AUs in the elastic potential energy of the spring during its launch of the marble? (c) What is the spring constant of the spring? (a) Number Units (b) Number Units (c) Number Units

Because of friction, a constant force of 20 N is needed to slide a box across a room to the right at a constant speed: a) How many Newtons must the friction force be? b) How much work is done by the friction force? c) How much work is done by gravity? d) How much work is done by the normal (upward) force? e) What is the net work done?

A 5 kg block is pushed 3 meters along a frictionless horizontal table by a constant 20 N (20 Newtons) force directed 60 degrees above the horizontal. The work done by the applied force is: A.)Work done by the applied force = 100 J B.)Work done by the applied force = 300 J C.)Work done by the applied force = 30 J D.)Work done by the applied force = 60 J

A 35 kg box is dragged by a rope a distance of 3 m from rest to a speed of 2m/s along a horizontal floor. The rope is at an angle of 25o from horizontal and has a tension of 65N. What is the work done by the tension and what is the work done by friction?

A man wishes to pull a crate 15m across a rough floor by exerting a force of 100 N. The coefficient of kinetic friction is 0.25. For the man to do the least work, the angle between the force and the horizontal should be: A. 0 B. 14? C. 43? D. 66? E. 76?   according to the memo, the answer is A. 0 degrees.  please explain why.  i was under the impression that work done is at its maximum when the angle between the force and displacement is zero, so 0 degrees would be the most incorrect answer. thank you.

1. How far must a 12N force pull a 150g toy car if 600 J of energy are transferred? distance m 2. An object is pushed by 4 m when a force of 200 N is applied on it on an inclined surface which is at an angle of 50 with the horizontal. What is the work done? Answer