Question

Une or
CONQUER TI
27 A car is moving with velocity 108 km/h, if driver
of car want to change its velocity from 108 km/h
to 90 km/h in two minutes, mass of the car is 300
kg. What force applied by the brakes on the tyres?
(a) 12N
(b) 12.5 N
(c)-12 N
(d) -12.5 N​

Answer 1

Answer:

Given that ,

Initial Velocity = 108km/h

To change it in m/s , we multiple by 5/18

$= 108 \times \frac{5}{18}$

= 30m/s

Final velocity = 90km/h

=25m/s

Time taken = 2 mins = 2× 60 = 120 seconds.

$acceleration = \frac{v - u}{t}$

$acceleration = \frac{5}{120}$

$= \frac{1}{24} m \: per \: {s}^{2}$

We know that ,

Force = Mass × Acceleration

= 300× 1/24

= 12.5 N

So , Correct answer will be option A

Hope it helps you :)