Question

A car is moving with a velocity of 72km/h when brakes are applied it comes to rest after three seconds find tha distance traveled by it befor coming to rest

Answer 1

Here since the car stops it's final velocity will be zero.
Given initial velocity = 72km/hr
We need to change it into m/s
=
$72 \times \frac{5}{18} \\ = 20$
20m/s


So acceleration =

$\frac{v - u}{t}$
v = final velocity
u = initial velocity
t = time

So acceleration =
$\frac{0 - 20}{3} \\ = \frac{ - 20}{3}$
Negative sign means acceleration is in opposite direction of velocity.

So Distance travelled (s) =
$ut + \frac{1}{2} at {}^{2} \\ \\ = 20 \times 3 + \frac{1}{2} \times \frac{20}{3} \times 9 \\ = 60 + 30 \\ = 90$
90 metre


Hope it helps dear friend ☺️✌️✌️