Question

A car is moving with speed u, comes to rest due to retardation of brake and Distance travel by car is 10 meter. If same car travels with speed 2u instead of u then find distance travel by car before coming to rest will be. (in both case retardation is same)​

Answer 1

Answer:

By Newton's third law of motion

v

2

−u

2

=2as

here acceleration a is negative since it is retardation, displacement s is the stopping distance d, u is the initial velocity and v is the final velocity.

Since the objects tops after the motion, v=0

thus

−u

2

=−2ad

d=

2a

u

Let take d

1

as the distance traveled by the car with velocity u and d

2

as the distance traveled by the car with velocity 4u.

The retardation for both the car is −a

d

2

d

1

=

2a

u

2

(4u)

2

2a

d

2

d

1

=

16

1