A bus is travelling at a constant speed of along a straight road when the driver sees…
PHYSICS · Multi-part · CBSE · Physics · Motion in a Straight Line · Motion in a Straight Line
Problem
A bus is travelling at a constant speed of 15m/s along a straight road when the driver sees a red traffic signal 40m ahead. Assume all motion is along one dimension.
(a) If the brakes are applied instantaneously and the bus decelerates uniformly to rest exactly at the traffic signal, calculate the required acceleration.
(b) In reality, the driver takes 1.0s to react before pressing the brakes. During this reaction time the bus continues at 15m/s. Recalculate the uniform acceleration needed after the brakes are applied so that the bus still stops at the traffic signal.
(c) Compare the stopping distances with and without the reaction time and explain briefly why the reaction time makes such a significant difference.