Question

A car is moving at a speed of 25km/h and come to rest. The time taken for the car to come to rest is 2 hr. Find the acceleration of the car and distance travelled

Answer 1

Explanation:

u = 25 km/hr

as it comes to rest so v = 0

t = 2hr

so by using v = u + at

0 = 25 + a*2

-25 = a*2

a = -25/2 = 12.5km/hr^2

for distance S = ut + 1/2 at^2

= 25*2 +1/2 12.5*2^2

=50+1/2 * 12.5*4

= 50+ 25

= 75km

Answer 2

in the first fig I have found the acceleration by putting it's formula

in the second fig I have solved the distance travelled by using the third equation of motion