You compress a spring by x and then release it. Next you compress the spring by 3x. How much more work did you do the second time than the first? A) 9 times as much B) 3 times as much C) 1/3 as mich D) we need the springs constant to decide E) the same

Please help me with this question:  1. Bob a man with a mass of 90kg, climbs up a 3.5m high tree. a.) How much work must Bob do in order to make it to the top of the tree, assuming that he begins and ends at rest?    Bob now jumps out of the tree and land on the ground.  b.) How fast will he be going just before he hits the ground?   c.) First assume that he forgets to bend his knees. That means that he wil land hard - the cushions on his feet will make him move downward 1.6cm while coming to a stop, but that's it. How much force will he feel from the ground while he stops?    d.) As you can see, that enormous force result in a everely injured Bob. So rewind, and let's assum Bob bends his knees this time. That means that the ground forced is in contact with him while he moves 0.45cm downward. Now how much force will the ground exert on Bob?

The work done by a horizontal spring as it is being compressed from its unstretched position is   a. positive     b. negative     c. either positive or negative, depending on where you start   d. depends on how fast you are moving       e. none of the above because work is a scalar that cannot be referred to as positive or negative

A 50 kg skier leaves the top of a 10 m high frictionless slope (point "a") from rest and reaches the bottom of the slope (point "") with a speed v,. He subsequently continues sliding on level ground to a full stop to a point "c" due to friction (i.e. 0.2 on the level ground). a. Write an expression for the total mechanical energy of the skier at point "a". b. Write an expression for the total mechanical energy of the skier at point "b". c. Use the Work-Energy Theorem to determine the work done from point “b" to point “c".

you become angry with physics and throw your 1kg book across the room. If the speed of the book after it leaves your hand is 30 m/s, how much work did you do on the book? Assume the height of the book doesnt change.

150.0 J of work is done while lifting a 200.0 N box 0.75 meters up over your head towards a shelf. Given this information, how much P.E. does the box after it was raised? A) 0 J B) 150 J C) 266.67 J D) 1102.5 J E) don't be silly, it's none of these!