1.
A body starts from rest and accelerates uniformly at 4 m/s². What is its velocity after 5 seconds?
A
10 m/s
B
20 m/s
C
25 m/s
D
15 m/s
Answer and explanation
Correct Answer: B — 20 m/s
Using v = u + at. u = 0, a = 4 m/s², t = 5 s. v = 0 + 4 × 5 = 20 m/s.