<em>Answer 1: Stress is defined as a force that can cause a change in an object or a physical body while strain is the change in the form or shape of the object or physical body on which stress is applied.</em>
<em>Answer 2: Stress can occur without strain, but strain cannot occur with the absence of stress.</em>
While stress is a type of pressure given by force acting per unit area. Strain is the ratio of change in length and total length when stress occurs. Ratio of stress and strain gives Young's Modulus. The curve between stress and stress is linear as long as they are proportional to each other.
I believe that it's an exhausted bear. Cellular respiration is the way plants and animals receive energy. If the bear is exhausted, it means it's cellular respiration is lacking.
They speed up chemical reactions. Without them you wouldn't be alive. They break down macromolecules, and also lower the amount of energy needed for a chemical reaction to happen.
