Two magnets are stuck together when a physics student pulls them apart and holds them close to each other so she can still feel them pulling on each other. How does pulling the magnets apart affect their magnetic potential energy?

A. stays the same
B. decreases by one half
C. magnets cannot create potential energy
D. magnets only have potential energy when they are touching each other
E. increases

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

How is the acceleration of an object in uniform circular motion constant? a - in magnitude only b - in direction only c - in both magnitude and direction d - in magnitude, direction & orientation

Galileos view of arrangement of the universe