Question

A water pump with a power of 3.4 × 102 watts lifts water at the rate of 7.5 × 10-2 meters/second from a water tank. What is the force exerted by the pump on the water?
A.
1.5 × 103 newtons
B.
2.2 × 103 newtons
C.
4.5 × 103 newtons
D.
5.4 × 103 newtons

Answer 1

Hello!

The answer is:

The correct option is:

C. $4.5x10^{3}N$

Why?

To calculate the force exerted by the pump, we must remember the formula to calculate power, also, we must remember that power means work done in a determined period of time.

We have that power can be calculated by the following equation:

$Power(W)=F*V=N.\frac{m}{s}=\frac{N.m}{s}=1Watt$

So, we are given the following information:

$Power=3.4x10^{2}W=340W=340\frac{N.m}{s}\\\\V=\frac{7.5x^{-2}m }{s}=\frac{0.075m}{s}$

Now, substituting and calculating we have:

$Power(W)=F*V$

$340\frac{N.m}{s}=F*\frac{0.075m}{s}$

$F=\frac{340\frac{N.m}{s}}{\frac{0.075m}{s}}=4,533N=4.5x10^{3}N$

Hence, the correct option is:

C. $4.5x10^{3}N$

Have a nice day!