The equations of motion to use for a constant acceleration a = g = -9.81:


at the highest point the velocity must be zero:

combine both equations:

Solve for v₀:
Answer:
Gravitational potential energy (GPE) = 107.8J
Explanation:
Gravitational potential energy (GPE) = mgh
Where mass(m) = 11kg
Acceleration due to gravity(g) = 9.8m²/s
height = assumed to be 1m
Force(F) = mg
Force(F) = 11×9.8 = 107.8N
Gravitational potential energy (GPE) = 107.8×1
= 107.8J
When the winch is pulling it up it's first hill, it is losing it's energy to give it to the coaster. It starts gaining energy because its height. Then when it goes down the hill, gravity kicks in and the potential energy turns into kinetic energy.
Evidence for the particle nature of light are not: 1. refraction, 2. many colors of light, 3. diffraction. These are all phenomenon that support wave theory of light. Evidence for particle nature of light is photoelectric effect. Because it was discovered that you need discrete energies of light to eject electrons from a metal surface and not continuous as the wave theory of light suggests.