Question

A body having mass 20kg travels 100m distance ,its velocity decreases from 20m/s to 5m/s .Force in the body is......

Answer 1

v2=u2+2as
5^2=20^2+2a×100
a=18.75m/s^2
F=ma
=20×18.75
=375N

Answer 2

Hi dear,

Your answer is here_________--------»

Use work energy theoram ➡️➡️

Work done = change in KE

$work \: done = f.s \\ change \: in \: kinetic \: energy = \frac{1}{2} m {v}^{2} - \frac{1}{2} m {u}^{2} \\ f.100 = \frac{1}{2} m( {v}^{2} - {u}^{2} ) \\ 10f = {5}^{2} - {20}^{2} \\ 10f = 25 - 400 \\ 10f = - 375 \\ f = \frac{ - 375}{10} \\ f = - 37.5newton$
➡️➡️Force will be -37.5 N