Question

A car of mass 200kg moving at 36km/hr is brought to rest after it covered a distance of 10m. Find the retarding force acting on the car

Answer 1

converting speed into m/s = 36×5/18=10m/s
$v {}^{2} - u {}^{2} = 2as$
0-10×10=2a×10
-100=20a
a=-100/20
a=-5m/s^2

Retarding force = ma
F=200×5
F=1000N
negative sign is removed as it is already mentioned that force is retarding.

Answer 2

0-10×10=2a×10

-100=20a

a=-100/20

a=-5m/s^2

Retarding force = ma

F=200×5

F=1000N

negative sign is removed as it is already mentioned that force is retarding