C. during the same time span and from the same material as the sun
Answer:
The frequencies are 
Explanation:
From the question we are told that
The speed of the wave is 
The length of vibrating clothesline is 
Generally the fundamental frequency is mathematically represented as

=> 
=> 
Now this other frequencies of vibration experience by the clotheslines are know as harmonics and they are obtained by integer multiple of the fundamental frequency
So
The frequencies are mathematically represented as

=> 
Where n = 1, 2, 3 ....
True because heat energy moves to the warmer areas.
They have a north and South Pole .The opposite poles attract to each other ,the same poles repel from each other.
Answer: 2.67 m/s
Explanation:
Given
Mass of block A is 
mass of block B is 
The initial velocity of block A 
the initial velocity of block B is 
After collision velocity of block A is 
Conserving momentum

The momentum of block A after the collision is 
Therefore, there is no change in sign.