# Speed of bowling ball involving speed of sound

## Homework Statement

A bowling ball traveling with a constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting pins 2.5 s after ball is released from his hands. What is the speed of ball, assuming speed of sound is 340 m/s?

## Homework Equations

the kinematic equations
x=x0+v0t+.5at^2
v=v0+at
vf^2=v0^2+2ax

## The Attempt at a Solution

Well, I thought that somehow I could use the time it takes for the sound wave to travel up and down the bowling lane, which is (33 m)/(340 m/s)= about .097 s. See I can picture the problem in my head, but I don't know how to get t for the ball in order to find the speed.

Nidum
Gold Member
Hint : start by working out the time taken for sound to travel one direction back from pins to bowler .

Hint : start by working out the time taken for sound to travel one direction back from pins to bowler .
Are you asking the time it takes sound to travel just to end of lane?

Are you asking the time it takes sound to travel just to end of lane?
Then wouldn't the time be about .049 s to travel from the pins to you?

Nidum
Gold Member
So how long does ball take to travel from bowler to pins ?

Hint : start by working out the time taken for sound to travel one direction back from pins to bowler .
Now, since I hear the ball hitting the pins 2.5 s after I throw it, then the time it takes the ball to hit the pins= 2.5 s - .049 s =2.45 s. Now to find velocity I do v= change in r/change in t= 16.5 m/2.45 s= 6.73 m/s is speed of ball.

So how long does ball take to travel from bowler to pins ?
.049 s.

Nidum