Answer:
(a) h = 16.53 m (b) t = 1.83 s
Explanation:
Given that,
The initial velocity of a ball, u = 18 m/s
When it reaches to the maximum height, its final velocity v will be 0. Let it goes to a maximum height of h meters.
Finding t using first equation of motion as follows :
v = u +at
Here, a = -g and v = 0
[tex]t=\dfrac{u}{g}\\\\t=\dfrac{18}{9.8}\\\\t=1.83\ s[/tex]
The time needed for the ball to reach its max height is 1.83 s.
Let h is the maximum height. Using second equation of motion to find it :
[tex]h=ut-\dfrac{1}{2}gt^2\\\\h=18(1.83)-\dfrac{1}{2}\times 9.8\times (1.83)^2\\\\h=16.53\ m[/tex]
So, it will go to a maximum height of 16.53 m.