Arock at the top of a 20 meter tall hill. the rock has a mass of 10 kg. how much potentail energy does it have?

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.

What would be the strength of earth's gravitational field at a point where an 80.0 kg astronaut would experience a 80% reduction in weight

Aracecar driver has to hold on tightly when going around a banked curve. approximately what is the centripetal force on a 2220.0 kg car going around a circle with a diameter of 190.0 meters at 25.0 m/s?