Answer:
t = 1.24 seconds
Explanation:
Given that,
Velocity of the ball, u = 30 m/s
Height, h = 45 m
We need to find how much time will it take the ball to reach a height of 45 m. Let the time be t.
Using the second equation of motion to find it.
[tex]h=ut+\dfrac{1}{2}at^2\\\\45=30t+\dfrac{1}{2}\times 9.8\times t^2\\\\45=30t+4.9t^2\\\\30t+4.9t^2-45=0\\\\t=1.24\ s\ \text{and}\ -7.36\ s[/tex]
Neglecting negative value,
The ball will reach to a height of 45 m in 1.24 seconds.
