What is the magnitude of the average force required to stop an 1200 kg car in 9.0 s if the car is traveling at 80 km/h? Express your answer using two significant figures.

Answer: 2960N

Explanation:

According to newtons first law of motion, force = mass * acceleration

To get acceleration,

Acceleration = velocity/time

Velocity = 80km/hr

Converting the velocity to m/s

80*1000/1*3600

velocity = 22.2m/s

Time = 9secs

Acceleration=22.2/9

Acceleration = 2.47m/s²

The get the force

F = 1200*2.47

F = 2960N