please check my answers.

17. explain how the sport of pole vaulting dramatically changed when flexible fiberglass poles replaced still wodden poles?
-the fiberglass poles had more momentum and PE than still wooden poles?

20. does the international space station have gravitational pe? ke? explain?
-It has gravitation pe, but I am stuck as to why?

25. what does the work theorem say about the speed of a satillite in circular orbit? (this one I don't understand)

30.a moving hammer hits a nail and drives it into a wall. if the hammer hits the nail with twice the speed, how much deeper will the nail be driven? if it hits with three times the speed?
-would it be three times the speed

no, yes but why, no , no

fiberglass poles can store energy (from horizontal velocity) and transfer it upward.

Gravational PE occurs when two bodies are separated, right?

The satellite in orbit uses no energy.

work = velocity^2
force*distance=velocity^2
distance is proportional to velocity^2
so what is twice square?

17. Your answer is partially correct. When flexible fiberglass poles replaced still wooden poles in pole vaulting, it did result in increased momentum and potential energy. However, it is important to understand the physics behind it. Fiberglass poles store more elastic potential energy due to their ability to flex and bend during the jump. As the vaulter plants the pole in the ground and pushes off, the stored elastic potential energy is released, propelling the vaulter higher into the air.

20. Yes, the International Space Station (ISS) does have both gravitational potential energy (PE) and kinetic energy (KE). Gravitational potential energy is present because the ISS is in orbit around the Earth, and it is influenced by the Earth's gravitational field. The higher the altitude of the ISS, the greater its gravitational potential energy.

As for kinetic energy, the ISS is moving at a very high speed in its orbit. Kinetic energy is associated with the motion of an object, so the ISS has a significant amount of KE due to its fast orbital velocity. Both PE and KE are important in understanding the energy dynamics of objects in space.

25. The work theorem states that the work done by the net force on an object is equal to the change in its kinetic energy. In the case of a satellite in a circular orbit, the net force acting on it is the gravitational force, which always points inward. Since the satellite is moving in a circular path at a constant speed, there is no change in its kinetic energy. This means that the net work done on the satellite is zero.

In simpler terms, the work theorem is saying that the work done on the satellite is balanced by its gravitational potential energy. The satellite remains in a stable circular orbit because the work done by gravity is equal to the change in its kinetic energy, resulting in a constant speed.

30. When a moving hammer hits a nail and drives it into a wall, the depth to which the nail is driven is influenced by the speed at which the hammer strikes it. Assuming all other factors remain constant (such as hammer weight and angle), the depth of the nail is directly proportional to the square of the speed at which the hammer hits.

So, if the hammer hits the nail with twice the speed, the nail will be driven four times as deep. If it hits with three times the speed, the nail will be driven nine times as deep. The relationship is quadratic, meaning that the depth is proportional to the square of the speed.