Larger than one.
In fact, the index of refraction of a medium is the ratio between the speed of light in vacuum (c) and the speed of light in that medium (v):
But the maximum speed the light can travel at is exactly c, the speed of light in vacuum: so v is always less (or equal, in case of vacuum) than c, and so n is always greater than 1.
B because radio waves make a sound that are short
Explanation:
T = 2π √(L / g)
1.0 s = 2π √(L / 19.6 m/s²)
L = 0.50 m
The solution for this problem is:
Work it backwards: spring U = ½kx² = ½ * 4000N/m * (0.10m) ²
= 20 J
so the pre-impact of KE = 20 J = ½ * m * v² = ½ * 0.40kg * v²
v = 10 m/s → for the bullet/block.
Now conserve the momentum:
50g * u = 400g * 10m/s
u = 80 m/s is the arrow
velocity
The distance must be one-third the original distance should be your answer! Hope this helps! :D