Question

A tennis ball is thrown vertically upward with
an initial velocity of +9.3 m/s.
What will the ball’s velocity be when it
returns to its starting point? The acceleration
of gravity is 9.81 m/s^2


How long will the ball take to reach its starting
point?

Answer 1

It should have the same velocity.
Projectile motion is like a parabola.

Answer 2

Since the ball is launched vertically against gravity force at 9.3 m/s, then it will also fall back down from the peak and have the same velocity of 9.3 m/s at ground start point

equations:
y = Voy * t - 1/2 g * t^2
and Vy = Voy - gt

Vy = velocity of object in y direction
Voy = initial vertical velocity
t = time in seconds
y = distance in vertical meters
g = 9.81 m/s^2

Solving for y, the object goes 4.4 meters high
solving for t:
t = 0.95 seconds for trajectory time