Answer:
<em>An average net force of 5200 N is needed to stop the car</em>
Explanation:
<u>Cinematics and Dynamics</u>
Cinematics describes the variables involved in the movement without dealing with its causes. There are four main concepts in cinematics: Velocity (or its scalar equivalent, the speed), acceleration, time, and displacement (or the scalar equivalent, distance).
The acceleration can be calculated by:
The initial speed is vo=28 m/s, it stops (vf=0) in t=10.5 seconds, thus the acceleration is:
The acceleration is negative because the car loses speed.
Knowing the mass of the car m=1950 Kg, we can calculate the net force required to stop the car by using the formula:
F = m.a =1950*2.67
F = 5200 N
An average net force of 5200 N is needed to stop the car