Answer
a. Knee movement : Mechanical energy
b. Digesting food : Chemical energy
c. Ions moving across cell membranes : Electrical energy
d. UV waves : Radiant energy
Work Step by Step
A. Knee movement consists of mechanical energy because it involves movement of matter.
B. Digesting food involves chemical reactions that breaks down complex molecules into simple molecules, which is a involves chemical energy.
C. Electrically charged ions moving across cell membranes involves electrical energy.
D. UV wave is a radiation, which contains radiant energy.
