A parallelogram rotates about its center. At what angle of rotation will the image of the parallelogram coincide with its preimage? A. 30° B. 90° C. 180° D. 270° E. 315°.

What accounts for an increase in the temperature of a gas that is kept at constant volume? a. energy has been removed as heat from the gas. b. energy has been added as heat to the gas. c. energy has been removed as work done by the gas. d. energy has been added as work done by the gas.