# Homework Help: Kinematics bowling ball problem

1. Sep 3, 2004

### physicsss

a bowling ball traveling with constant speed hits the pins at the end of a bowling lane 10 m long. The bowler hears the sound of the ball hitting the pins 3 sec after the ball is released from his hands. What is the speed of the ball? (Speed of sound is 340 m/s)

Can someone give me a hint? I know it involves d=v*t, but I don't know how I can use the speed of sound and the time when the ball hits the pins besides finding the distance the ball traveled...

Last edited: Sep 3, 2004
2. Sep 3, 2004

### jamesrc

The total time between releasing the ball and hearing the sound of the ball hitting the pin is given as 3 seconds. This time, T, is the sum of t1, the time it takes the bowling ball to go down the lane, and t2, the time it takes for the sound to travel 10m. (T = t1 + t2) for t2, v = a = d/t2, where a is the speed of sound and d is 10 m. The same equation goes for t1: vball = d/t1. (the speed of the ball is unknown) To put it all together, solve for t1 and t2 and plug back into the first equation I wrote. I hope that helps.

Last edited: Sep 3, 2004
3. Sep 3, 2004

### physicsss

tell me if I'm on the right track...

3=t1+t2
3=t1+(d/v)
3=t1+10/340
t1=2.97

d=vt
10=v*2.97
v=3.4 <-velocity of the ball

Last edited: Sep 3, 2004
4. Sep 3, 2004

### jamesrc

Looks good except for the second line, which looks like a typo. Speaking of which, I had a typo in my original post (fixed now, sorry about that). Anyway, good job.

5. Sep 3, 2004

### physicsss

Fixed, and thank you so much for the help.