Calculate the braking force for a car of mass 1200 kg travelling at 12 m/s if its braking distance at that speed is 20 m.

Sure, let's calculate the braking force step by step.

1. First, we need to calculate the kinetic energy of the car using the formula: KE = 1/2 * m * v^2 Where m is the mass of the car and v is its velocity. So, KE = 1/2 * 1200 kg * (12 m/s)^2 = 86,400 Joules

2. Next, we need to calculate the work done to stop the car. The work done is equal to the kinetic energy of the car, which is 86,400 Joules.

3. The work done is also equal to the force applied times the distance over which it is applied (W = F * d). We can rearrange this formula to solve for the force: F = W / d

4. Substituting the values we have: F = 86,400 Joules / 20 m = 4320 N

So, the braking force required to stop the car is 4320 Newtons.