Projectile Motion - Example Problem 3.2-6

 

From a videotape, it was observed that a pro golfer hit a golf ball 126 yards for a hole in one. The duration of the golf ball’s flight was measured to be 5.6 seconds. Determine the initial speed of the ball and the angle θ at which it was struck.

 

 

Given:

• D = 126 yd = 378 ft
• t_C = 5.6 s

 

Find:

• v_o
• θ

 

Solution:

 

Video solution:

 

The following video walks you through the solution to this problem. It is suggested that you try solving the problem first and then, if you have difficulties with the solution, watch the video for help.

 

 

Interactive solution:

 

When solving projectile problems, it is a good idea to label the important points of motion (e.g. the start, the apex, the end).

 

Click on the figure to see how this problem was labeled.

 

It is usually a good strategy to start analyzing a projectile problem in the x-direction.

 

Starting with the x-direction, find an equation for D.

 

D = v_osin(θ) t_C
D = v_ocos(θ) t_B
D = v_ocos(θ) t_C