Answer:
The initial speed of the ball is 3.93 m/s.
Explanation:
It is given that,
A ball is thrown horizontally from a height of 19 m, h = 19 m
Let u is the initial speed of the ball so, its final velocity, v = 5u
Using third equation of motion as :
[tex]v^2-u^2=2gh[/tex]
[tex](5u)^2-u^2=2\times 9.8\times 19[/tex]
[tex]24u^2=372.4[/tex]
u = 3.93 m/s
So, the initial speed of the ball is 3.93 m/s. Hence, this is the required solution.
