Air Track Experiment: Explaining the Velocity Increase

[mathsgeek]

I have just done an experiment with a glider on an air track and applied a force to it. Its velocity increased very slightly and was wondering are there any reasons, other than friction, why the velocity could change during motion? Thanks

I thought this but i don't know if its right "There is a logical explanation for why the velocity of the glider increased during motion for reasons other than friction. This is due to the air discharged by the air track, used to make the glider float and eliminate friction, disturbed the glider and possibly applied a small force to the glider, making the glider’s velocity increase by a small fraction. While there is force being applied by the air underneath the glider to keep it afloat, some of the air particles from the air that is discharged and is not covered by the glider, located on either side of the glider, may have applied this force. "

Any suggestions would help.

 

[jtbell]

Are you sure the air track was perfectly straight and perfectly horizontal?

 

[mathsgeek]

Yes I am pretty sure, a lab technician actually did it so i would assume they would know How to do it. Is my suggestion incorrect? Tell me your suggestions how it would increase motion if it wasnt perfctly straight or the way other factos could have affected it? Thanks very much, I am having trouble thinking of any.

 

[rcgldr]

If the force wasn't applied to the exact center of the glider, then a small angle would result, causing a change in velocity.

 

[mathsgeek]

Could you explain it a bit more cause i don't really understand it? Thanks. Any other suggestions would help also

 

[rcgldr]

If one end of the glider is relatively heavier than the other end, then it will rest at an angle on the upwards air flow, and since it's at an angle, the "forwards" air flow from the glider will be different than the "backwards" air flow, resulting the in a change in velocity of the glider. If the "front end" is heavier, the glider moves forwards, and vice versa.

 

[mathsgeek]

Thanks. Btw what do you mean by "fowards" and "backwards" air flow?

 

[rcgldr]

What do you mean by "fowards" and "backwards" air flow?

That there would be a net component of forward or backward air flow if the glider were at an angle. Air would tend to flow towards the end with the larger gap.