- #1
sa1988
- 222
- 23
Hi all, new user here and straight in with a question to help me understand something. Not sure if I'm in the right sub-forum but oh well.
Regarding circular motion and centripetal acceleration, we're given the classic example of a cyclist leaning into a corner to create a general equilibrium against the friction and the weight in the system, to allow for the resultant centripetal acceleration.
Also there's the example of rolling a coin along a surface. If the coin loses balance, it describes circles until it stops. If the coin were to somehow be going at constant velocity, and then it leant to one side, it would go in circles forever, right?
So my confusion is regarding the rigid body turning in a circle when made to lean. The coin does it, as can be observed quite easily by anyone. But... what about a two-wheel object such as a bicycle? If the front and rear wheel were rigidly locked in a straight line (so it's not really a bicycle but a rigid body with two inline wheels), would it still describe circles if it were made to lean? Or does bicycle turning actually involve a slight element of turning the handlebars?
I'll be honest, I'm just trying to clear something up on a motorcycle forum I use. I reckoned it's possible to make any rigid body turn by leaning it (not using handlebars at all), and so I used the coin analogy as an example, but then someone else said that it wouldn't be possible if there were two wheels rigidly inline with each other, and if you leaned you would just toppled over.
Intuitively it sounds like the guy is right, but then... another niggling bit of intuition tells me the bike should turn?
Which intuition is correct?!
Thanks all
Regarding circular motion and centripetal acceleration, we're given the classic example of a cyclist leaning into a corner to create a general equilibrium against the friction and the weight in the system, to allow for the resultant centripetal acceleration.
Also there's the example of rolling a coin along a surface. If the coin loses balance, it describes circles until it stops. If the coin were to somehow be going at constant velocity, and then it leant to one side, it would go in circles forever, right?
So my confusion is regarding the rigid body turning in a circle when made to lean. The coin does it, as can be observed quite easily by anyone. But... what about a two-wheel object such as a bicycle? If the front and rear wheel were rigidly locked in a straight line (so it's not really a bicycle but a rigid body with two inline wheels), would it still describe circles if it were made to lean? Or does bicycle turning actually involve a slight element of turning the handlebars?
I'll be honest, I'm just trying to clear something up on a motorcycle forum I use. I reckoned it's possible to make any rigid body turn by leaning it (not using handlebars at all), and so I used the coin analogy as an example, but then someone else said that it wouldn't be possible if there were two wheels rigidly inline with each other, and if you leaned you would just toppled over.
Intuitively it sounds like the guy is right, but then... another niggling bit of intuition tells me the bike should turn?
Which intuition is correct?!
Thanks all