Answer:
The rate at which work is done is power

According to above question ~
Let's find the charge (q) by using formula ~
Hence, 12 coulombs of charge flow past any point in the wire in 3 seconds
Answer:

Explanation:
The two cars are under an uniform linear motion. So, the distance traveled by them is given by:

is the same for both cars when the second one catches up with the first. If we take as reference point the initial position of the second car, we have:

We have
. Thus, solving for t:

Answer:
At an angle of 
Explanation:
Assume the river flows from East to West so for the swimmer to cross across it, assume he crosses it from West to East.
The resultant speed will be given by

Answer:
A. evaporation
Explanation:
Evaporation is a surface phenomenon as the molecules of the surface gets sufficient energy to overcome the force of attraction which will help in converting to the vapor phase.