An electric elevator with a motor at the top has a cable weighing 4.5 pounds per foot. When the car is at the first floor, 180 feet of cable are out, and effectively 0 feet are out when the car is at the top floor. The elevator car itself weighs 2000 pounds when empty   a) Find the work done by the motor lifting just the empty elevator car from the first floor to the top floor, ignoring the cable. b) Find the work done by the motor lifting just the cable from the first floor to the top floor. Keep in mind, that the cable gets shorter and must therefore get lighter as the elevator goes up.

i) A small 25g toy rocket is launched straight up from the ground at 144 km/h (a) What is the  kinetic energy of the toy rocket? (b) Find the work done by gravity after it has risen 220 m. (i) (a). The kinetic energy of the toy rocket is = (b). The work done by gravity after it has risen 220 m is =

A 2 kg object initially at rest is pushed along a frictionless surface by a constant force of 10 N for a distance of 5 meters. Calculate the work done on the object and its resulting final velocity.

Find the work done in joules by gravity as an object of the mass m 5 kg is raised up at constant speed from a height h;=26 m to a height h2=69 m. Consider g = 10 m/s2 A. None B. -2150 D. -6450 E. -4300 O < O a OUO DOE

An elevator having a mass of 585 kg is raised a distance of 32 m. Determine the work done, neglecting frictional effects and the work required for acceleration.

A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is O twice as much. None of the given choices one-fourth as much. one-half as much. O four times as much.

Use Maple

Problem 2: Suppose a car approaches a hill and has an initial speed of 108 km/h at the bottom of the hill. The driver takes her foot off of the gas pedal and allows the car to coast up the hill. a) If the car has the initial speed stated at a height of h = 0, how high, in meters, can the car coast up a hill if work done by friction is negligible?  b) If, in actuality, a 770-kg car with an initial speed of 108 km/h is observed to coast up a hill and stops at a height 20.5m above its starting point, how much thermal energy was generated by friction in J?

16-2. A block of mass 2.56 kg is pushed 2.00 m along a frictionless horizontal table by a constant16.5 N force directed 25.3◦ below the horizontal. Determine the work done by (a) theapplied force, (b) the normal force exerted by the table, (c) the force of gravity, and (d) thenet force on the block.Brainstorm ideas that will help you solve this problem(a) Determine the work done by the applied force.(b) Determine the work done by the normal force exerted by the table.(c) Determine the work done by the force of gravity.(d) Determine the work done by the net force on the block.       my understanding is that work is equal to force times displacment. I figured that a) is 33 j and since b) and c) the object doesn't move up or down it is 0. However I am not certain. Please help!

- A person lowering a 50 N block over 0.8 m. Determine the work done by the string on the block as the block is lowered 0.80 m. The string tension is 50 N. : A person is pulling a 50 N block up a 60 deg. incline over 0.8 m. Determine the work done by the string on the block as the block is lifted 0.80 m along the incline. The string tension is 50 N.