inclined planes

[aronno]

1 - can a=gsin(theta) be applied to any inclined situation.

2- DOES "constant retarding forces" mean a=0 like "constant spd?"

3- Net force in inclined planes when there is constant frictional force, what does it mean?
is it saying that a=0 ? when we resolve the forces in the inlcined situation.

4- When should i make/know that a=0. WHEN resolving forces paralell to the inclined plane?

this really urgent!!! please members, can you give me a detailed response.

[/0]

1. Yes, that's the acceleration down the slope due to gravity. But if you want you have to take into account other forces which could affect the net force, for example friction.
If the inclined plane is a 'banked curve', and you are racing around it, the situation becomes different. Here, the net acceleration will depend on the radius of the track, speed of motion etc. but if it is not a banked curve you don't need to worry about these things.
And of course, make sure that is the angle made with the horizontal, not some other random angle.

2. No, is not necessarily zero. Constant retarding forces just means the forces opposing motion are constant. (The forces which aid motion are normally called driving forces. .) The retarding forces may be constant, but the driving force could be bigger or smaller, giving a net force and net acceleration.

3. When there is friction, the net force DOWN the slope is , and the net force UP the slope is . If then there IS acceleration, but if then you have constant velocity.

4. if and only if . Calculate the forces down the slope (e.g. ) and the forces up the slope (e.g. friction) and any other forces such as tensions. And if the forces up the slope balance the forces down the slope, .