A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The player sees the ball land 20 m down range. What is the player's pitching speed?
A)5 m/s
B)10 m/s
C)20 m/s
D)25 m/s
E)none of the above

Question

Quizplus · Accepted Answer

The ball's initial velocity (horizontal) can be found using the equation: 
v = d/t 
where v is the horizontal velocity, d is the distance traveled, and t is the time taken.

Since the ball is thrown horizontally, there is no initial vertical velocity, hence we can use: 
d = (1/2)g*t^2 
where g is the acceleration due to gravity (9.8 m/s^2), and t is the time taken for the ball to land.

Combining these equations, we get: 
v = d / (sqrt(2*h/g))
where h is the initial height of the ball (5 m in this case).

Plugging in the values, we get: 
v = 20 / (sqrt(2*5/9.8)) = 20 m/s.

Therefore, the player's pitching speed is 20 m/s.

A Ball Player Wishes to Determine Pitching Speed by Throwing