Question

A driver of a car travelling at 52km/hr applies brakes and

accelerates uniformly in the opposite direction the car stops in 5

seconds. Another driver going at 34km/hr in another car applies brakes

slowly and stops in 10 seconds.​

Answer 1

Answer:

Given : 

First Car  A: 

Initial Velocity= u= 52 km/hr=52x5/18=14.4 m/s

Final velocity= V= 0m/s

time =t=5sec

Refer attachment for Graph :

Distance travelled : Area of traingle AOB =1/2 OB x AO

=(1/2)x 14.4 x 5=72/2=36m

Second Car  B:

Initial Velocity= u= 3 km/hr=3x5/18=0.83m/s

Final velocity= V= 0m/s

time =t=10sec

Refer attachment for Graph :

Distance travelled : Area of traingle COD =1/2 OD x CO=(1/2)x 0.83 x 10=4.1m

So, after applying of brakes , Car A has travelled a distance of 3m and car B has travelled a distance of 4.1m.

∴ Car B has travelled farther than Car A after the brakes are applied.

Explanation:

Answer 2

Answer:

Conversatio from Km/h to m/s

1 km=1000m

1 hr=60minutes=3600seconds

:.1km=1000m

hr 3600sec

:. 1km/hr=5/18m/s

CAR 1

Initial velocity=52km/h

=52 x 5

18

=130

18

=14.44m/s

Final velocity=0m/s

Time=5 seconds

CAR 2

Initial velocity=5km