Physics Problem.

[SweetScientist]

Hi guys thanks for reading.

 

I was looking at Newtons Laws and an analogy popped up about the motorcycle ball of death. (The large ball that people on motorcycles travel around.)

 

Ok, since Newtons first law states an object will move in a straight line unless acted on by an unbalanced force.

Since this track is curved, an unbalanced force will need to act on the motorcycle to make it turn.

Does this mean the engine has to apply the constant unbalanced force and continually accelerate for this stunt to work?

 

Thanks for any help guys.

[TonyMcC]

Hi guys thanks for reading.

 

I was looking at Newtons Laws and an analogy popped up about the motorcycle ball of death. (The large ball that people on motorcycles travel around.)

 

Ok, since Newtons first law states an object will move in a straight line unless acted on by an unbalanced force.

Since this track is curved, an unbalanced force will need to act on the motorcycle to make it turn.

Does this mean the engine has to apply the constant unbalanced force and continually accelerate for this stunt to work?

 

Thanks for any help guys.

I find this interesting. I see it another way. The rider on the bike will keep the speed as constant as he can so any instrument he has will be steady so he would say he is not accelerating. Let's say he is riding on a vertical surface at a constant height above the ground. He will hold the throttle at a steady position. His machine will be pressed into the wall by a combination of gravity and centrifugal force which will make his effective weight greater. Will he have to keep the throttle more open than he would if travelling normally on a straight road? Is he having to use more fuel? Is he effectively climbing an incline as far as his machine is concerned? Is he using enough fuel to accelerate if he was travelling in a straight line on a horizontal surface? I won't say what I think as this is homework. (Perhaps, even probably, I don't actually know the answers - lol)

Edited February 14, 2012 by TonyMcC

[DrRocket]

Hi guys thanks for reading.

 

I was looking at Newtons Laws and an analogy popped up about the motorcycle ball of death. (The large ball that people on motorcycles travel around.)

 

Ok, since Newtons first law states an object will move in a straight line unless acted on by an unbalanced force.

Since this track is curved, an unbalanced force will need to act on the motorcycle to make it turn.

Does this mean the engine has to apply the constant unbalanced force and continually accelerate for this stunt to work?

 

Thanks for any help guys.

d

 

No. The force that causes the acceleration (change in direction is an acceleration, even at constant speed) is supplied by the reaction force of the structure acting on the tires of the motorcycle. The force that results from the torque applied to the drive wheel is tangent to the path of the motorcycle and hence does not cause a direction change.

 

But the moltorcycle is in fact constantly accelerating. It is just that the acceleration need not be due to the action of the motorcycld engine. Any object traveling in an arc is constantly accelerating. That includes the Earth in orbit around the sun.

 

I find this interesting. I see it another way. The rider on the bike will keep the speed as constant as he can so any instrument he has will be steady so he would say he is not accelerating.

 

Incorrect.

 

He is in fact constantly accelerating by virtue of change in direction. This acceleration will be measured by any 3-dimensional accelerometer that he might have. Centripetal acceleration is real acceleration.

[TonyMcC]

 

Incorrect.

 

He is in fact constantly accelerating by virtue of change in direction. This acceleration will be measured by any 3-dimensional accelerometer that he might have. Centripetal acceleration is real acceleration.

 

I agree - I was thinking of normal motorcycle instruments i.e. a speedometer. I was hoping that what you say might be worked out from my post.

Edited February 14, 2012 by TonyMcC

[SweetScientist]

Thanks for the help guys! Gotta love that about Physics. Thought this would be a really simple problem but there's a whole lot of cool stuff involved. Learned a few new things!

 

So since the velocity is changing (ie: the direction component) it is deemed as acceleration. Even if the speed component is constant? Interesting stuff. I must point out I'm relatively(lol) inexperienced on the physics front so I apologize if this is a bit simpleton.