A car of mass m, travelling at speed v, stops in time t when maximum braking force is applied. Assuming the braking force is same for both cases, what time would be required to stop a car of mass 2 m travelling at speed v?

Question

A car of mass m, travelling at speed v, stops in time t when maximum braking force is applied. Assuming the braking force is same for both cases, what time would be required to stop a car of mass 2 m travelling at speed v? (A) (1/2) t (B) t (C) √2 t (D) 2t

Tardigrade Admin · Accepted Answer

Let the acceleration of first car be a. Then acceleration of second car is. For first car, 0 = v - at or t = (v/a) For second car, 0 = v -(a/2) t' or t' = (2v/a) = 2t

Q. A car of mass $m$ , travelling at speed $v$ , stops in time $t$ when maximum braking force is applied. Assuming the braking force is same for both cases, what time would be required to stop a car of mass $2 m$ travelling at speed v?

$\frac{1}{2} t$

t

$2 t$

2t

Let the acceleration of first car be a.
Then acceleration of second car is.
For first car, $0 = v - a t$ or $t = \frac{v}{a}$
For second car, $0 = v - \frac{a}{2} t^{'}$ or
$t^{'} = \frac{2 v}{a} = 2 t$

Q. A car of mass m, travelling at speed v, stops in time t when maximum braking force is applied. Assuming the braking force is same for both cases, what time would be required to stop a car of mass 2m travelling at speed v?

21​t

t

2​t

2t

Let the acceleration of first car be a. Then acceleration of second car is. For first car, 0=v−at or t=av​ For second car, 0=v−2a​t′ or t′=a2v​=2t

Q. A car of mass $m$ , travelling at speed $v$ , stops in time $t$ when maximum braking force is applied. Assuming the braking force is same for both cases, what time would be required to stop a car of mass $2 m$ travelling at speed v?

$\frac{1}{2} t$

$2 t$

Let the acceleration of first car be a.
Then acceleration of second car is.
For first car, $0 = v - a t$ or $t = \frac{v}{a}$
For second car, $0 = v - \frac{a}{2} t^{'}$ or
$t^{'} = \frac{2 v}{a} = 2 t$