A ball is thrown up from the top of a tower with 20 m/s velocity. It took the ball 6 sec to fall to the bottom. How much distance did the ball cover in the last second of its motion?
35 cm
Last second is the 6th second
(Displacement at t = 6) - (displacement at t = 5) should give us the answer.
=20(6)+12(−10)(6)2−[20(5)+12(−10)52]
= 120 - 180 - [100 - 125]
= - 60 - [-25]
= - 60 + 25
= - 35m
∴Answer = 35m as we are asking for distance.