[sakurabunny24]

Hi, I am confused with a couple questions for physics. The teacher didn't really do a good job of explaining, so I'm totally stumped. Can I just have a walk through of what I should do?
1. A box moved up a ramp with an incline of 35° with a velocity of 20 m/s. How far will it travel up the ramp before it stops?
2. A spring toy of mass 300g is compressed 5cm. It is then released a reaches a maximum height.
If the spring constant is 2800 N/m, what is the maximum height the toy reaches? What is the speed of the toy when it hits the ground?
3. A 5.0 kg ball is held at the top of a 325m tall building.
If you set the zero point at the top of the building, what is the ball's potential energy? If the zero point is 100m above the ball's starting position what is the balls potential energy? If you set the zero point at ground level, what is the ball's velocity at the very bottom?

[ebaines]

We won't provide the answers, but I can give a hint or two to get you started:

1. A box moved up a ramp with an incline of 35° with a velocity of 20 m/s. How far will it travel up the ramp before it stops?

Think about conservation of energy. Assuming no friction on the ramp, the box has an initial kinetic energy, KE=(1/2)mv^2, which is traded off for increase in potential energy as it slides up the ramp of delta PE=mgh.

2. A spring toy of mass 300g is compressed 5cm. It is then released a reaches a maximum height.
If the spring constant is 2800 N/m, what is the maximum height the toy reaches? What is the speed of the toy when it hits the ground?

Another energy problem. Set the PE of the compressed spring, (PE= (1/2)kx^2, equal to the KE of the toy as the spring uncompresses. Then set that equal to the gain in gravitational energy PE as it springs upward into the air.

3. A 5.0 kg ball is held at the top of a 325m tall building.
If you set the zero point at the top of the building, what is the ball's potential energy? If the zero point is 100m above the ball's starting position what is the balls potential energy? If you set the zero point at ground level, what is the ball's velocity at the very bottom?

The change in gravitational PE is delta PE=mgh, where h = height gained above a pre-defined "zero" point. It doesn't matter what the sero point is, as long as you are consistent with the math.