A762 kg car experiences a braking force of 9045 n and skids to a stop in 4.3 seconds. what is the speed of the car just before the braking force was applied?

The solution for this problem is:

We will be using the formula for force which is F = ma 

=>10,000 = 2000 * a 

but we need to solve for acceleration so divide both sides by 2000, we will get:

=>a = 5 m/s^2 

Let the initial velocity was u m/s 

=>By v = u - at 

=>0 = u - 5 x 6 

Since acceleration is constant the velocity can be computed by multiplying the acceleration by 6 seconds. 

=>u = 30 m/s

Explanation: