Question

A stone is thrown in a vertically upward direction with a velocity of 5 m/s . If the acceleration 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 ?

Answer 1

In the given question,the motion is one dimensional.
At maximum height the velocity of the stone must be 0.
By third equation of motion
${v}^{2} = {u}^{2} + 2as$
Upward direction is taken as positive,hence
v=0,u=5m/s and a=-10m/s²
putting these values,we get
${0}^{2} = {5}^{2} - 2 \times 10 \times s$
s=25/20=1.25m
By first equation of motion
v=u+at
0=5-10 x t
t=5/10=0.5 sec