how much energy is stored in the spring when it is stretched? *

A 73.1-kg skier rides a 2520-m-long lift to the top of a mountain. The lift makes an angle of 17.2 ° with the horizontal. What is the change in the skier's gravitational potential energy? Number i Units

A woman at the gym lifts a weight upwards. a) Does she do positive work on the weight, negative work on the weight, or no work on the weight? Explain how you know. b) Does the Earth (i.e. the force of gravity) do positive work on the weight, negative work on the weight, or no work on the weight? Explain how you know.

Two children have identical spring-loaded catapults, which contain springs with spring constant k. If Samir compresses the spring in his catapult by a distance x and Mona compresses hers by a distance 2x, how does the work they have done to compress their catapults compare? A. Mona has done 2 times as much work as Samir. B. Samir has done 2 times as much work as Mona. C. They have done the same amount of work. D. Mona has done 4 times as much work as Samir.

1. A roller-coaster car with a mass of 1200 kg starts at rest from a point 20 m above the ground. At point B, it is 9 m above the ground. [Express your answers in kilojoules (kJ).] a. What is the initial potential energy of the car? b. What is the potential energy at point B? c. If the initial kinetic energy was zero and the work done against friction between the starting point and point B is 40 000 J (40 kJ), what is the kinetic energy of the car at point B 2. The time required for one complete cycle of a mass oscillating at the end of a spring is 0.80 s. What is the frequency of oscillation?

Suppose a 1300-kg elevator car is lifted a distance 45 m by its cable at a constant speed, assuming the frictional force on the elevator has a constant value of 1350 N. 1.Calculate the work done on the elevator by its cable, in joules.  2.Calculate the work done by the gravitational force on the elevator, in joules, during this process.  3.Calculate the total work done on the elevator, in joules.

A 1000 kg sports car is initially traveling at 5 m/s . The driver then applies the brakes for several seconds so that 25 of net work is done on the car. Calculate the initial and final kinetic energy of the car.

A spring rests at a length of 0.5 m and is pulled to a length of 2 m. It has a spring constant of 3 N/m. What is the Eel of the spring when stretched?