Question

A car of mass 1800 kg moving with a speed of 10 m/s is brought to rest after covering a distance of 50 m calculate the force acting on the car

Answer 1

Using third law of 1d kinematics,
v^2-u^2=2as

Given,

s=50m; v=0; u=10m/s

Then,

v^2-u^2=2as
0-(10)^2=2a(50)
a= -1m/s

Force=mass×acceleration, (or) Force=mass×deceleration

Therefore,

Deceleration= -1m/s^2
Deceleration= -(acceleration)
Force=mass×deceleration
=1800×1
=1800N

Force will be acting in opposite direction to displacement of the car.

Answer 2

V²-u²=2as
-100= 2×50×a
a= -1 m/sec

F=ma
1800× -1
= - 1800 N

HOPE HELPS ✌️✌️