Question

a car of mass m= 1260kg is moving at 29.2 m/sThe driver begins to apply breaks so that magnitudeof braking force increases linearly with timethe rate of 3360N/S How much time passesbefore thecar comestorest.​

Answer 1

Given :-

Mass of car = m = 1260 Kg

Initial Velocity of car = 29.2 ms-¹

Braking Force = F = -3360t

As force will act in the opposite side.

F = ma

a = F/m

a = -3360t/1260

a = -2.6t

Integrating 'a'

$\int ^{v} _u \: v \: = \int^{t} _0 - 2t \: dt$

v - u = -2t²/2

v - 29.2 = - t²

As Final Velocity is Zero.

t² = 29.2

t = √29.2

t = 5.4 s