Tuesday, July 16, 2013

Load on stationary vehicle

Load on stationary vehicle



What are the Forces on a Moving Car?
The forces acting on a moving car are thrust and drag
as well as the same forces that act on a stationary car.



Drag is the force of air resistance (a form of friction)
pushing against the front of the car while it is moving.
Thrust is the force pushing the car forwards. Thrust comes from the engine turning the wheels.
How do Wheels make a Car go Forwards?
Tyres on the wheels push backwards against the road as they try to turn, causing an equal and opposite force which pushes the car forwards.





The tyres must have good grip (a high friction)
so that they do not slide on the road surface.
If the forces of thrust and drag are equal,
then the forces are balanced and
the car will move with a constant velocity.
If the forces of thrust and drag are not equal, then
the forces are unbalanced and the car will accelerate.
The car will get faster if thrust is bigger than drag,
and slower if the drag is bigger than the thrust.