Answer:
The last one is false
Explanation:
Energy can be neither created or destroyed. It can only move from one type of energy to another.
Answer:
d. velocity slows down and angle changes
Explanation:
Answer: waves transport energy, not water. As a wave crest passes, the water particles move in circular paths. The movement of the floating inner tube is simulacra to the movement of the water particles. Water particles rise as a wave crest approaches.
Explanation:
Answer:
w = 2w₀ the angular velocity of man doubles
Explanation:
In this exercise, releasing the weights reduces the moment of inertia
I= I₀ / 2
Therefore, since the platform system plus man is isolated, the kinetic moment must be conserved
L₀ = L
I₀ w₀ = I w
I₀ w₀ = I₀ / 2 w
w = 2w₀
therefore the angular velocity of man doubles
The rest energy of a particle is

where

is the rest mass of the particle and c is the speed of light.
The total energy of a relativistic particle is

where v is the speed of the particle.
We want the total energy of the particle to be twice its rest energy, so that

which means:


From which we find the ratio between the speed of the particle v and the speed of light c:

So, the particle should travel at 0.87c in order to have its total energy equal to twice its rest energy.