C. change length and direction
Explanation:
The density of the material in which the light wave is travelling affects the speed of the wave. Different materials have different densities and they effect differently light waves which travel through them. Light waves may change direction at the boundary between two transparent materials, depending on material density. Density also impacts the speed of light. The denser the material, the slower light travels through it. The wavelength also decreases as light travels through the denser medium.
Answer:
Im pretty sure 1 is gravity, 2 is force
Explanation:
Potential energy is first transformed into kinetic energy as she pedals, then gravitational as she coasts down the hill.
