Light from other stars take longer to reach the earth because they are farther than our sun.
        
                    
             
        
        
        
Answer:
<h3>The answer is option B</h3>
Explanation:
The frequency of a wave can be found by using the formula

where
c is the velocity
From the question
wavelength = 0.39 m
c = 86 m/s
We have

We have the final answer as
<h3>200 Hz</h3>
Hope this helps you
 
        
             
        
        
        
To solve this problem we will apply the concepts related to the balance of Forces, the centripetal Force and Newton's second law.
I will also attach a free body diagram that allows a better understanding of the problem.
For there to be a balance between weight and normal strength, these two must be equivalent to the centripetal Force, therefore


Here,
m = Net mass
 = Angular velocity
= Angular velocity
r = Radius 
W = Weight 
N = Normal Force 

The net mass is equivalent to

Then,

Replacing we have then, 

Solving to find the angular velocity we have,

Therefore the angular velocity is 0.309rad/s