Answer:
Acceleration, a = 750m/s²
Explanation:
Given the following data;
Radius, r = 0.31m
Velocity, v = 15m/s
To find the centripetal acceleration;

Substituting into the equation, we have;
Acceleration, a = 750m/s²
Therefore, the centripetal acceleration of the bike wheel is 750m/s².
Answer:
A. 
B. 
Explanation:
The frequency has an inversely proportional relationship with the concept of wavelength, the greater the wavelength, the lower the frequency. For electromagnetic waves, the frequency is equal to the speed of light, divided by the wavelength.

A.

B.

You would most likely be witnessing an eclipse