Question

A car is traveling at a velocity of 30 m/s. It then brakes over a displacement of 50 meters to come to rest. What was the acceleration of the car?

Answer 1

The acceleration of the car is  $9 m / \sec ^{2}$

Explanation:

Given:

Final velocity v = 0  m/s  

Initial velocity u = 30 m/s  

Stopping distance or displacement = 50 meters

To Find:

Acceleration of the car=?

Solution:

The third equation of motion is,

$v^{2}-u^{2}=2 a s$

Substituting the known values,

$v^{2}-u^{2}=2 a s$

$(30)^{2}-(0)^{2}=2(a)(50)$

$900=100 a$

$a=\frac{900}{100}$

$a=9 m / \sec ^{2}$