Question

The rate of doing work is called?
A- Power
B- Energy
C- Acceleration
D- velocity

Answer 1

Hint: We know we need to do work in order to get some output or to move any object. Mathematically and scientifically work is defined as the dot product of force with the displacement. Since in the dot product we need to take the cosine of the angle between the force vector and the displacement vector then the work can be zero, positive and negative since the value of cosine varies from -1 to +1.

Complete answer:
The statement says the rate of doing work. Whenever we come across the term rate, it means we are dividing the given quantity by the time. So, the question says we need to find work divided by time and we know that gives us the Power. Power gives us an idea how efficient the machine is. The SI unit of work is Joules and the SI unit of time is seconds, thus, the SI unit of power comes out to be J/s and it is known as Watt (W).
So, the rate of doing work is called power.

So, the correct answer is “Option A”.

Note:
Power may be defined as the rate of doing work or the rate of using energy. These two definitions are equivalent since one unit of energy must be used to do one unit of work. There can be different forms of power such as mechanical power or electric power. Power can also be written as the dot product of force with the velocity. Commonly used unit of power is horsepower (hp).