Question

A car driver driving at a speed of 90 km hour applies brakes and brings the car to rest in 20 second the acceleration of car is​

Answer 1

Answer:

-4.5km/hr

Explanation:

a=(v-u)÷t

a=(0-90)÷20

= -4.5 (here - (negative sign ) shows retardation

Answer 2

Answer:

The car had deacceleration of 1.5 m/s²

Explanation:

As per the data given in the question,

We have,

Initial velocity of the car(u) = 90 km/hr = 25 m/s

After stopping,

Final velocity of the car(v) = 0 m/s

Time taken to stop(t)= 20 sec

Applying formula, to calculate acceleration,

$v=u+at\\0=25+a\times20\\a=\frac{-25}{20}\\ a=-1.25\: m/s^{2}$

This means it had deacceleration of 1.5 m/s²

#SPJ2