Question

An electric motor creates a tension of $9000N$ in a hoisting cable and reels it in at the rate of $2m{s}^{-1}$. The power of the electric motor is

• A. $18kW$
• B. $15kW$
• C. $81W$
• D. $225W$

Answer 1

The correct option is A

$18kW$

Step 1: Given data

Tension force developed by an electric motor is $F=9000N$

Velocity of the motor is $v=2m{s}^{-1}.$

Step 2: Finding the power of the electric motor

We know that,

$$\begin{gathered} Power=Force\times velocity \\ P=9000\times 2 \\ P=18000W \\ P=18kW \end{gathered}$$

The power of the electric motor is 18 kW.

Hence, option (a) is correct.