A city bus travelling at 15 m s⁻¹ comes to rest uniformly in 0.50 s when the driver…
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
A city bus travelling at 15 m s⁻¹ comes to rest uniformly in 0.50 s when the driver applies the brakes.
(a) Determine the magnitude of the deceleration of the bus.
(b) Calculate the average magnitude of force that must act on a 60 kg passenger so that he comes to rest along with the bus in the same time interval. (Ignore all forces other than the belt tension.)
(c) If the seat belt stretches by 0.25 m while stopping the passenger, find the average work done on the passenger by the belt.
(d) Explain qualitatively why the stretchability of the belt reduces the chance of injury, even though the work done on the passenger is the same as in a rigid belt.