Answer:
105 m
Explanation:
Given that the initial velocity of the body, u= 50 m/s in upward direction.
Acceleration due to gravity, g= 10 m / [tex]s ^ 2[/tex] in the downward direction.
Let h be the height of the body when the velocity of the body is 20 m/s.
As the gravitational force acting in the downward direction, so taking it negative as
a= - 10 m/[tex]s ^ 2[/tex] in the upward direction.
By using the equation of motion [tex]v^2=u^2+2as[/tex] ...(i)
Here, u= 50 m/s
v= 20 m/s
[tex]a=- 10 m/s^2[/tex]
s=h
Putting all the values in the equation (i), we have
[tex]20^2=50^2+2(-10)h \\\\400=2500-20h \\\\h=\frac{2500-400}{20} \\\\h=105 m[/tex]
Hence, the height of the body is 105 m.