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Question
A stone is thrown in a vertically upward direction with a velocity of 5 m s-1. If the acceleration of the stone during its motion is 10 m s-2 in the downward direction, what will be the height attained by the stone and how much time will it take to reach there?
Solution
Initial velocity (u) = 5 ms−1
Final velocity (v) = 0
Acceleration (a) = -10 ms−2
First equation of motion
v = u + at
0 = 5 + (-10)t
t = 0.5 s
Third equation of motion
v2 = u2 + 2as
0 = 52 + 2 × (-10)s
s = `25/20`
= 1.25 m
Height reached by the stone = 1.25 m and time taken to reach = 0.5 s.
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