Question

a force displaces a 5kg body to 10m in 10 seconds and its velocity becomes 20m/sec Calculate the power delivered

Answer 1

power is 10 watt
I solved this and this is the best answer

Answer 2

Given :

Mass of body , M = 5  kg .

Displacement , d = 10 m .

Time taken , t = 10 s .

Final velocity , v = 20 m/sec .

To Find :

The power delivered .

Solution :

Let , initial velocity be u .

So , by equation of motion :

$s=ut+\dfrac{at^2}{2}\\\\10=u(10)+\dfrac{a(10)^2}{2}\\\\u+5a=1 \text{ ........eq 1 }$

Also by ,

$v=u+at\\\\10a+u =20 \text{ ....... eq 2}$

Solving equation 1 and 2 :

We get , $a=3.8\ m/s^2$ .

So , force applied :

$F=ma\\F=5\times 3.8 \ N\\F=19\ N$

Now , work done is given by :

$W=Fd=19\times 10=190\ J$

Power delivered is given by :

$P=\dfrac{W}{t}=\dfrac{190}{10}\ Watts\\\\P=19\ Watts$

Therefore , power delivered is 19 Watts .

Hence , this is the required solution .