(adsbygoogle = window.adsbygoogle || []).push({}); Linear Motion (I'm sure it is easy for all you out there)

Okay, so I'm not really getting this problem:

"A bowling ball traveling at constant speed hits the pins at the end of the lane, 20m away. If the bowler hears the "crack" of the ball hitting the pins 2.5 s after releasing the ball. If the speed of sound is 340m/s, what is the speed of the ball?"

My first thought is to use distance over time equals velocity (d/t=v)

So I thought that I might try 20m/2.5s, but that only tells me the velocity of a ball going down the lane... I'm not really sure how to incorporate the speed of sound within the 2.5 secs...

My next "problem" is: "A speeding motorist passes a stationary police officer at 120 km/h. If the officer immediately accelerates at 5 km/h/sec, how long before the officer catches the speeding motorist?"

For some reason my instinct in this situation is to go 120x = .5(5km\h\sec)(x)^2, but it just doesn't work...

So I thought that perhaps I could try converting the 120km/h to km/h/s: 120km/h/3600sec = .033km/h/s and I wanted to use x again, but I'm just at a loss of words...

Maybe I am biting off more than I can chew, but I am trying.

Thanks in advance for any help.

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# Homework Help: Linear Motion (I'm sure it is easy for all you majors out there)

**Physics Forums | Science Articles, Homework Help, Discussion**