Correct option: (B) 26ms–1, 10ms–1
Explanation:
initial velocity = 60 m/s
acceleration = 10 m/s also v = 60 + (– 10) (10) = 40 m/s
particle is thrown in upward direction. Its velocity will decrease till it reaches top and increases while coming down.
average speed in upward dirn = {(60 + 50 + 40 + 30 + 20 + 10 + 0) / 7} = 30 m/s
average speed in downward dirn = {(0 + 10 + 20 + 30 + 40) / 5} = 20 m/s
average speed = [{(30) × (6) + (20) × (4)} / {10}] = [{260} / {10}] = 26 m/s
average velocity = [{60 + (– 40)} / {2}]
= 10 m/s ----- taking downward velocity negative.