Formula for electrostatic potential energy between two charged particles change if one particles 's charge is reduced to a factor of 3?

a: increase by a factor of 9
b: decrease by a factor of 9
c: increase by a factor of 3
d: decrease by a factor of 3

Which changes of state do the labels represent? a: b: c:

Since the energy was not raising the temperature of the water during these segments, what was the energy used to do instead? your answer must include an explanation of what is happening to the molecules.

Aspring is used to stop a 50-kg package which is moving down a 20º incline. the spring has a constant k = 30 kn/m and is held by cables so that it is initially compressed 50 mm. knowing that the velocity of the package is 2 m/s when it is 8 m from the spring and neglecting friction, determine the maximum additional deformation of the spring in bringing the package to rest.