Question
To avoid an accident the brakes of a car travelling at 30 ms-1 were applied suddenly. If the driver has a mass of 80 kg and it takes 3.0 s for the car to decelerate to rest what is the average force exerted by the safety belt on the driver during deceleration?
Answer
We first calculate the acceleration of the driver.
The force by the safety belt provides the force that causes the deceleration.
Hence, the average force exerted by the safety belt on the driver is 800 N.