What is the correct reference frame for a given situation?

How much work does the charge escalator do to move 2.30 μc of charge from the negative terminal to the positive terminal of a 3.00 v battery?

An object is 10. cm from the mirror, its height is 3.0 cm, and the focal length is 2.0 cm. what is the image height? (indicate the object orientation by including the + or - sign with the answer.) hi = cm +1.33 -1.33 +0.75 -0.75

Which accounts for an increase in the temperature of a gas that is kept a constant volume