Q23 of 47 Page 8

A stone is thrown in 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?

According to the Question we have:-

Acceleration, a = - 10 m/s2 ( As the stone is thrown vertically upwards therefore the force of gravity will be acting on it in a downward direction)


Initial velocity, u = 5 m/s(Given)

Final velocity, v = 0 (As it stops at the top)

Distance travelled, s =?

We know that:-

v2-u2= 2as

Putting the values in above equation


(0)2- (5)2 = 2 × (-10) × s


0 -25 = 20 s


20 s = 25


s =

s = 1.25 m

Therefore, the height attained by the stone will be 1.25 metres


Now, we have to find out the time


As we know that:

v = u + at

0 = 5 + (-10) × t


0 = 5 – 10t


10t = 5


t =


t = 0.5 s


Therefore, 0.5 seconds will be taken by the stone to reach at the top.

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