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6 votes
6 votes
4. Brandon throws a tennis ball vertically upward. The ball returns to the point of release after 4.0 s. What is the

speed of the ball as it is released?

User Petr Hrehorovsky
by
2.5k points

1 Answer

22 votes
22 votes

Answer:

-39.2m/s

Step-by-step explanation:

Using the equation of motion;

v = u + at

Since the ball is thrown upward, the acceleration due to gravity acting on it will be negative, hence a = -g

v = u - gt

Since g = 9.8m/s²

t = 4.0s

u = 0m/s

v = 0 + (-9.8)(4)

v = 0 + (-9.8)(4)

v = -39.2m/s

Hence the speed of the ball before release is -39.2m/s

User James Ruskin
by
2.6k points