What is the impulse of a 131g baseball when it strikes a batter at 57 m/s
1 answer:
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Answer:
v = 2,425 m / s
Explanation:
A simple pendulum has anergy stored at the highest point of the path and this energy is conserved throughout the movement.
highest point
Em₀ = U = m g y
lowest point
= K = ½ m v²
Em₀ = Em_{f}
mg y = ½ m v²
v = √ 2gy
let's calculate
v = √ (2 9.8 0.3)
v = 2,425 m / s
Answer:
B) waves speed up
C) waves bend away from the normal
Explanation:
The index of refraction of a material is the ratio between the speed of light in a vacuum and the speed of light in that medium:
where
c is the speed of light in a vacuum
v is the speed of light in the medium
We can re-arrange this equation as:
So from this we already see that if the index of refraction is lower, the speed of light in the medium will be higher, so one correct option is
B) waves speed up
Moreover, when light enters a medium bends according to Snell's Law:
where
are the index of refraction of the 1st and 2nd medium
are the angles made by the incident ray and refracted ray with the normal to the interface
We can rewrite the equation as
So we see that if the index of refraction of the second medium is lower (), then the ratio
is larger than 1, so the angle of refraction is larger than the angle of incidence:
This means that the wave will bend away from the normal. So the other correct option is
C) waves bend away from the normal