A particle has the following velocity–time description:
• From t=0 to t=4s, its velocity increases uniformly from 0 to 20ms−1.
• From t=4s to t=8s, its velocity remains constant at 20ms−1.
Which statement about the particle’s acceleration during 0–8s is correct?
(a) It is 5ms−2 throughout the entire 8s.
(b) It is 2.5ms−2 throughout the entire 8s.
(c) It is 5ms−2 for the first 4s and 0 for the next 4s.
(d) It is 10ms−2 for the first 4s and 0 for the next 4s.