Question

A car was running at a speed of 50km/h suddenly the driver applied the brake to bring the car in rest and it takes 5seconds , find out the value of acceleration

Answer 1

Answer:

The acceleration is -25/9 m/s².  

Explanation:

Given :

A car was running at a speed of 50 km/h, suddenly the driver applied the brakes to bring the car to rest and it takes 5 seconds.

To find :

the value of acceleration

Solution :

Initial velocity, u = 50 km/h

Converting km/h to m/s :

$\rm =50 \times \dfrac{5}{18} \: m/s \\\\ \rm =\dfrac{250}{18} \: m/s \\\\ \rm =\dfrac{125}{9} \: m/s$

Final velocity, v = 0 m/s

time taken, t = 5 seconds

Using v = u + at ,

$\sf 0 =\dfrac{125}{9}+a(5) \\\\ \sf 5a=\dfrac{-125}{9} \\\\ \sf a=\dfrac{-125}{9 \times 5} \\\\ \sf a=\dfrac{-125}{45} \\\\ \sf a= \dfrac{-25}{9} \: m/s^2$

Therefore, the acceleration is -25/9 m/s².