Question

1. A spring loaded pistol with a spring constant of 360 N/m holds a 0.06 kg steel marble and is compressed 0.1 m. If the pistol is aimed horizontally, how fast (in m/s) will the steel marble be as it exits the barrel of the pistol?

2. A 6.2 kg cat walks up a few flight of stairs and ends up 14 m above its beginning location. How much work did it take the cat to accomplish this task?

3. A 760 N diver drops from a board 13 m above the water's surface. Find the diver's speed (in m/s) just before striking the water.

Answer 1

So I'm still not fully certain about the correct formulas to use, but here's my view of it:

1.
I believe that you need to first use Hooke's law to find the spring force, then find the elastic potential energy stored in the bow. Then, given the law of conservation of energy, you can solve for velocity from kinetic energy. Get that?

Answer 2

wait it isn't a bow...i mean bullet/marble lol

Answer 3

for 2.

You are using the work formula, W=Fd. You have distance. You can find force using F=ma, and since he's walking up, he's using an upward force, so let a=g=9.18.

Answer 4

@dingas2002 I hope it helped. BTW, I'm not sure about #3. #1 and #2 are certainly correct if you use the method I told you.

Answer 5

If someone else wants to give a try for #3, go for it. I couldn't figure out as yet. But you definitely need to find mass and do something with mass and distance.