Ramps for wheel chairs are usually made long and not very steep, so
that you don't need to apply much force to the wheelchair to get it to
go up the ramp. If the ramp were steep, you would have to push harder.
Ramps for wheel chairs are usually made long and not very steep, so
that you don't need to apply much force to the wheelchair to get it to
go up the ramp. If the ramp were steep, you would have to push harder.
Steep hills have signs on them to warn truckers that they will have to be careful to keep the forces balanced, lest they lose control.
Think of a heavy purse hanging from your shoulder. The net force on the purse (unless it is changing its motion) is zero. There are actually two forces acting on the purse. You apply one of them, pulling it up, while gravity provides the other, pulling it down. They cancel out so the purse just hangs there, not jerking upwards or dropping.