A car is travelling at when the driver presses the accelerator
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A car is travelling at 5m/s when the driver presses the accelerator. The car then:
• Accelerates uniformly at 2m/s2 for 5s.
• Immediately afterwards, decelerates uniformly at 1m/s2 for 8s.
Answer the following questions, using clear and systematic calculations:
(a) What is the velocity of the car at the end of the first 5s?
(b) What is its velocity at the end of the next 8s (the end of the whole 13s)?
(c) Determine the average acceleration of the car for the complete 13s interval.
(d) Calculate the total displacement of the car during the 13s.
(e) Compare the magnitude of the average acceleration obtained in part (iii) with the accelerations in each phase and give a reason for the observed value.