Sorry if this has been already asked, but I've been looking around google for a while and couldn't find an answer suitable. I'm a beginning physics student so pardon the dumb question.
Let's say we let a block slide down a ramp of angle $\theta$. I know the component down the ramp is equal to $mg \sin \theta$ and the component normal to the ramp is mg cos theta. Since $F = ma$, $mg \sin \theta = ma$, and the masses cancel right? But this is without friction. So my question is does mass affect the speed of an object (down a ramp for example, or even in free fall) when there is friction/air resistance?
Some thoughts...I guess it would be written as $F = ma = mg \sin \theta - uF_N = u mg \cos \theta$. So mass still doesn't matter right?
One more question. Let's say we have an object moving at a constant velocity on a rough surface with friction, so some force is applied. Will adding mass to the object slow it down? Common sense says yes, but why?