A baseball thrown from the outfield is released from shoulder height at an initial velocity of 28.3 m/s at an initial angle of 30.0° with respect to the horizontal.If it is in its trajectory for a total of 4.00 s before being caught by the third baseman at an equal shoulder-height level,what is the ball's net vertical displacement during its 4.00-s trajectory?
A)98.0 m
B)9.80 m
C)10.2 m
D)zero
E)20.4 m

Question

A baseball thrown from the outfield is released from shoulder height at an initial velocity of 28.3 m/s at an initial angle of 30.0° with respect to the horizontal.If it is in its trajectory for a total of 4.00 s before being caught by the third baseman at an equal shoulder-height level,what is the ball's net vertical displacement during its 4.00-s trajectory?​
A)98.0 m
B)9.80 m
C)10.2 m
D)zero
E)​20.4 m

Quizplus · Accepted Answer

The net vertical displacement of the ball is zero because it is caught at the same height it was released from. The horizontal displacement is given by: 
$$
x = v_{0x}t = (28.3\ \mathrm{m/s})\cos(30°)(4.00\ \mathrm{s}) = 92.4\ \mathrm{m}
$$
but this information is not necessary to determine the vertical displacement.

A Baseball Thrown from the Outfield Is Released from Shoulder