Question

3
A car moving with speed v on a straight track can
be stopped in a distance x by applying brakes. If
same car is moving with speed 2v and brakes
provide half the retardation then car will stop after
travelling distance
​

Answer 1

Answer:

required distance = 8x

Explanation:

Case - 1:

let the acceleration = -a

Initial velocity = v

final velocity = 0

displacement = x

so,

v^2 - 2ax = 0

=> a = v^2 / 2x ........ (i)

Case-2:

Initial velocity = 2v

final velocity = 0

acceleration = -a/2

so,

s = {0 - (2v)^2} / 2(-a/2) = 4v^2 / a

= 4 × 2x

= 8x ........

required distance = 8x

Answer 2

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