According to the law of conservation of energy, what can happen to the total energy of a system?
A. The total energy can increase if energy is transferred into the
system from surroundings.
B. The total energy can decrease when energy is lost due to energy
transformation within the system.
C. Energy must be transferred out of a system if energy is
transferred into the system so that they total energy of the system
stays the same.
D. The total energy must remain the same, but energy can change
forms and be transferred within the system.

Clara is shopping in a grocery store with her friend. each has their own shopping cart in which they want to place their items. the shopping carts are identical. clara and her friend add the same type and number of items to each of their carts. in the baking aisle, however, clara adds 20 pounds of sugar to her own cart, and her friend adds only 10 pounds of sugar to her own cart. which of the following statements best explains what clara must do to accelerate at the same rate as her friend? a. she must add more sugar to her cart. b. she must apply more force to move her cart. c. she must add 20 pounds of salt instead of 20 pounds of sugar to her cart. d. she must apply less force to move her cart.