Answer:
Explanation:
Let's answer these statements
.1) True. This is the law of reflection.
.2) False. The speed of light depends on the index of refraction n = c / v
v = c / n
.3) True. The frequency creates a forced oscillation, whereby the atoms re-emit at the same incident frequency
.4) False. The index of refraction is a measure of the ratio of the speed of light in a vacuum and the material environment, the ability to change the trajectory is given by the law of refraction
.5) True. True due to the change in beam trajectory due to the law of refraction
.6 False. The phenomenon occurs when you pass from a medium with a higher index to one with a lower ratio, because the refracted beam separates from the normal
.7) True.
.8) False so that the lightning approach is valid Lam >> d,
.9) True.
Answer: Looked it up but
Explanation:
When the skater lands on the track, the vertical component of his kinetic energy is converted to thermal energy. You can do experiments where there is no loss to thermal energy (only PE and KE conversions) by turning friction off and by making sure the skater doesn't leave the track.
Answer:
1.8 s
Explanation:
Potential energy = kinetic energy + rotational energy
mgh = ½ mv² + ½ Iω²
For a thin spherical shell, I = ⅔ mr².
mgh = ½ mv² + ½ (⅔ mr²) ω²
mgh = ½ mv² + ⅓ mr²ω²
For rolling without slipping, v = ωr.
mgh = ½ mv² + ⅓ mv²
mgh = ⅚ mv²
gh = ⅚ v²
v = √(1.2gh)
v = √(1.2 × 9.81 m/s² × 4.8 m sin 39.4°)
v = 5.47 m/s
The acceleration down the incline is constant, so given:
Δx = 4.8 m
v₀ = 0 m/s
v = 5.47 m/s
Find: t
Δx = ½ (v + v₀) t
t = 2Δx / (v + v₀)
t = 2 (4.8 m) / (5.47 m/s + 0 m/s)
t = 1.76 s
Rounding to two significant figures, it takes 1.8 seconds.
