Question

A motor boat moves at a steady speed of 4ms-1. water resistance acting on it is 4000N calculate the power of its engine

Answer 1

Given Data:

Velocity= v = 4ms-1

Force= F = 4000N

Find Out:

Power=P= ?

Solution:

Formula of Power

$p = \frac{w}{t}$

where:

P is the Power

W is work done by thy body

t is the time taken by the body to complete its work

We know that

1. W= F×S

2. W= F×S÷t

3. W= F×v

where:

F is the Force

S is the Distance

t is the Time

v is the Velocity

For Explanation/Understanding

1. As we know that work done by a body is equal to force applied to it and the distance covered by it due to its motion

2. As the body takes time to reach a point we divide t

3. Here, we can observe that S÷t is the formula of velocity

So simply we put v instead of s÷t

Now the formula becomes

$p = f \times v$

$p = 4000 \times 4 \\ = 16000 \: w$

Unit of Power = Watt or W

So, the power of engine of a motor boat moving with a steady speed of 4ms-1 with water resistance of 4000N is 16000W.