The rate at which work is done is .

The rate at which work is done is called power.

Explanation:

The rate at which work is done is called power. It is also known as rate of doing work. Mathematically, it is given by :

Where

W is the work done by the force

t is the time taken

Since, W = F × d and

So,

The SI unit of power is watts.

Hence, this is the required solution.

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray