Question

An engine moves a motorboat through water at a constant velocity of 22 meters/second. If the force exerted by the motor on the boat is 5.75 × 103 newtons, what is the power of the motor? A. 7.9 × 104 watts B. 1.3 × 105 watts C. 2.5 × 105 watts D. 3.7 × 105 watts E. 5.0 × 105 watts

Answer 1

Answer: Option B: 1.3×10⁵ W

Explanation:

$Power = \frac{Work \hspace{1mm} done}{Time}$

$P=\frac{W}{t}$

Work Done, $W= F.s$

Where s is displacement in the direction of force and F is force.

$\Rightarrow P = \frac{F.s}{t} =F \times \frac{s}{t}=F.v$

where, v is the velocity.

It is given that, F = 5.75 × 10³N

v = 22 m/s

P = 5.75 × 10³N×22 m/s = 126.5 × 10³ W ≈1.3×10⁵W

Thus, the correct option is B