Physics Puzzle: The Rear of a Bicycle & the Front of a Car

[Moon]

In Ireland, 16 year olds are expected to answer this question at some point during the leaving cert physics course. I’m finding it difficult to answer. Can anyone help me here? Ah, nothing like sharing wisdom...

The rear of a bicycle passes a point P on a road and travels at a steady speed of 12 m s-1 down the road. At the same instant, the front of a car starts from rest at P and moves in the same direction as the bicycle with an acceleration of 12 m s-2. When and how far from P does the front of the car catch up with the rear of the bicycle?

Good luck! I’m looking for the actual workings too.

 

[quantumdude]

Hi Moon, and welcome to Physics Forums.

Originally posted by Moon
Good luck! I’m looking for the actual workings too.

Funny, that's just what I'd like to say to you!

We have a policy here: We don't do your homework for you. Please read the announcement at the top of this Forum:

https://www.physicsforums.com/showthread.php?threadid=28

Give it a shot, and post what you come up with. We will help you through the rough spots.

 

[jcsd]

Consider the equations:

s = ½(u +v)t and s = ut + ½at²

You can work it out using just these two equations.

 

[Moon]

Apologies there, but my problem is with how to use the data given in the question with the equation.

If anyone could at least break it down for me so I can do the equation work myself, which would help greatly.

 

[jcsd]

Ok, you see the two equations I've given you to find t by using the fact that though s is unkown it is the same for both the bicycle and the car.

 

[jcsd]

It's also helpful if you show what you've done so far.

 

[mcintyre_ie]

Wow. So I am not the only person in ireland struggling with physics?

 

[Moon]

Cool, where in Ireland do you live?

I figured out the problem eventually...

 

[mcintyre_ie]

The west. Was stupid enough to do higher maths, physics and applied maths for the Leaving, so this is where i turn to for help. What about you?