Physics help ...

[worth]

I need some physics help--If you have a car on a hill, how many forces are acting on it?

I said 3--normal force, gravity force, friction force that makes the car stand still, but I guess you could say 1 since if there was no gravity there would be no normal force, thus normal and friction forces could be considered components of gravity?

 

[silverpig]

If it's just sitting there, then it's the three you said. If it's moving, then there's drag as well.

 

[Bomberboy]

the only force acting on the car would be the force of gravity COS 0. fg sin 0 = fn so they cancel. Also, there would be a force of friction if the surface is not frictionless

 

[JohnCU]

Fn, Fw, Fp, friction.

 

[Rallispec]

you have MG (mass * gravity) acting straight down
the normal force acting perpindicular to the hill
the friction force going up the hill (keeping the car from rolling down the hill, if the car was moving up the hill, friction would be acting down the hill... friction always opposes motion)

 

[ApacheXMD]

you can also say there's an inertia force equal to ma which is opposing the direction of motion. But that's kind of a fake force.

-patchy