A car is initially moving at a speed of 25 km/hr when the brakes are applied, resulting in a constant deceleration that brings the car to rest in 15 m. Assuming the same constant deceleration, what would the stopping distance be if the initial speed were 50 km/hr

To solve this problem we will apply the linear motion kinematic equations. For which the change of the initial and final velocity is described, as the product of twice the acceleration and the distance traveled. This equation is independent of time, so it is conducive to this exercise.

We will start converting the units.

The definition of the linear equation of kinematic motion states that

Here,

= Final velocity

= Initial velocity

a = Acceleration

x = Displacement

Rearranging to find the acceleration,

Replacing,

Now we know that speed is

Then the distance traveled, starting from the same previous equations would be

false

explanation: