Answer:
The initial velocity was 9.39 m/s
Explanation:
<em>Lets explain how to solve the problem</em>
The ball is thrown straight upward with initial velocity u
The ball reaches a maximum height of 4.5 m
At the maximum height velocity v = 0
The acceleration of gravity is -9.8 m/s²
We need to find the initial velocity
The best rule to find the initial velocity is <em>v² = u² + 2ah</em>, where v is
the final velocity, u is the initial velocity, a is the acceleration of
gravity and h is the height
⇒ v = 0 , h = 4.5 m , a = -9.8 m/s²
⇒ 0 = u² + 2(-9.8)(4.5)
⇒ 0 = u² - 88.2
Add 88.2 to both sides
⇒ 88.2 = u²
Take square root for both sides
⇒ u = 9.39 m/s
<em>The initial velocity was 9.39 m/s</em>
