A power loss can be from a dead or almost-dead battery.
If the car loses power on a hill, it might be a fuel injector or fuel pump, if I'm not mistaken.
If a car shakes and loses power when idling it can be the spark plug. If a spark plug is fouling, it can cause power losses.
Try changing the fuel filter.
gravity
Same as any car with power steering. You can continue to steer the car but with increased effort.
what year is your car and engine cylinders
It loses power because going uphill is harder then going downhill therefore causing it to use more gas and then making it lose power bit by bit.
When your truck loses power, the ABS system loses power.
Have vehicle scanned to determine the problem
Sounds like it is in need of a complete tune up.
Since cars are very careless, they keep losing things such as power. And once lost, these things are very difficult to find!
you should check your battery cables first and make sure they are tight. then if still losing power check the connections going to your alternator. What you probrably have is a lose connection somewhere, so tighten everything you see.. :)
Far too vague for diagnoses. Far too many possibilities.