Question

A CAR OF MASS 800 KG IS MOVING WITH A SPEED OF 20 M/S. IT COMES AT REST AFTER 5 S WHEN A BRAKE IS APPLIED ON IT. FIND OUT THE RETARDATION AND THE RATARDING FORCE ACTING ON IT.

Answer 1

$\textbf{\underline{\underline{EXPLANATION:}}}</p><p>$

$\textbf{\underline{Given,,}}</p><p>$

Mass of car,m=800kg

Initial speed,u=20 m/s

final speed,v=0m/s (Since the car comes at rest)

time taken,t=5s

when the break is applied on the car then its retardation,

$\mathbf{\boxed{\blue{a=\frac{v-u}{t}}}}$

$\mathbf{\implies{a=\frac{0-20}{5}}}$

$\mathbf{\implies{a=-4ms^{-2}}}$

$\textbf{\underline{Now,,}}</p><p>$

$\textbf{The retarding force acting on car,}</p><p>$

$\mathbf{\boxed{\blue{F=ma}}}$

$\mathbf{\implies{F=800\times{-4}kgms^{-2}}}$

$\mathbf{\implies{F=-3200N}}$

Hope it helps ❣️❣️