A stone is thrown in a vertically upward direction with a velocity of 5 m/s

CBSE Class 9
1

A stone is thrown in a vertically upward direction with a velocity of 5 m/s.if the acceleration of the stone during the motion is 10 m/s in the downward direction, what will be the height attained by the stone and how much time will it take to reach there.

2

To find the height attained,
v2 = u2 + 2as
s = Height attained = (v2 - u2)/2a = (0 - 25)/(2 x -10) = 1.25 .
a is negative since it’s direction is opposite to the direction of motion.
t = (v - u)/a = -5/-10 = 0.5 s.