Which process is an example of a physical change?

a) carrots are cut into small pieces and mixed into a salad.

b) a peanut butter sandwich is eaten and broken down by enzymes and a flammable gas.

c) sodium metal and water are combined to form a basic compound and a flammable gas.

d) sodium metal and chlorine gas are combined to form a sodium chlorine, or table salt.

Option A

Carrots are cut into small pieces and mixed into a salad

Explanation:

When physical changes occur, the actual composition remain the same but the molecules are re-arranged. Therefore, when carrots are cut into smaller pieces and mixed into salad, there will be no chemical reaction hence the actual composition will remain the same despite being cut and molecules in it re-arranged. Considering the other options, new substances are formed hence they are deemed as chemical changes. Therefore, option A is correct.

potential energy is directly proportional to height.

more height = more potential energy.

greatest increase in height = greatest increase in potential energy

where are the points with the greatest increase in height ?

has to be c-e or d-e .