Question

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

Answer 1

u = 10 m/s
v = 0
s = 50 m
a = ?

Applying 3rd kinematic equation---
v^2 - u^2 = 2as
(0)^2 - (10)^2 = 2 x 50 x a
-100 = 100a
a = - 1 m/s^2

Now m = 1800 kg
a = - 1m/s^2

F = ma
F = 1800 x 1
F = - 1800 N

The force is acting in the opposite direction of the motion of the car

Hope This Helps You!

Answer 2

Given,
Mass = 1800 kg
initial velocity, u = 10m/s
final velocity, v = 0
distance, S = 50 m
Using third equation of motion,
i.e. 2as = v^2 - u^2
100a = -100
thus, a = -1

Force = mass x acceleration
= 1800 N in negative x direction