Question

A body is thrown up with a kinetic energy of $100J.$ Find the height attained by the body in the above case if mass of the body is $1kg.$

Answer 1

Step 1: Given data

Mass of the body m$=1kg$

The kinetic energy of the body when it is thrown up K.E$=100J$

Step 2: To find the height attained by the body.

we know that

K.E$=\frac{1}{2}m{v}^2$; where, v is velocity

$100=\frac{1}{2}\times 1\times v^2$

$v=14.142m{s}^{-1}$

when the body reaches the topmost point, the velocity becomes zero.

therefore final velocity be v' $=0m{s}^{-1}$

From the equations of motion we have,

$v^2-u^2=2as$; where, $v=v\text{'};u=v=14.142m{s}^{-1};a=-g;s=h=height$

$0-14.{142}^2=2\times (-10)\times h$

$h=10m$

Hence, the height attained by the body is $10m$.