Find the acceleration required to bring a 1500-kg car to rest from a speed of 100 km/h
within a distance of 55 m

The acceleration required to bring a 1500 kg car to rest is

Explanation:

As the car is bought to rest from the moving speed of 100 km/h, the deceleration exhibited by the car can be calculated provided the distance covered by the car before coming at rest. So the deceleration can be obtained using third equation of motion.

So in the present case, the displacement of the car before it came to rest i.e. s = 55 m, while the initial velocity will be the speed at which the car is moving and final velocity will be zero as the car will stop after travelling for 55 m. So the acceleration will be as below:

Thus,

Converting km to meter and hours to seconds, we get

So, the deceleration of the car is or we can also say that the acceleration attained by the car to come to rest is .

real, smaller and upside-down.   so the answer should be b.

double the distance = divide strength by 4