Question

The mechanical energy `(E)` of a body is the sum of kinetic energy `(K)` and potential energy `(V)` of the body i.e., `E = K + V`. Whereas `K` is always positive, `V` can be positive or negative. For a system to axis, `K = (E - V) ge 0`
Negative value of `E` indicates a bound state. For example, all planets revolving around the sum have nagative mechanical energy.
Read the above passage and answer the following questions :
(i) When mechanical energy `E = 0`, does it mean `K = 0 and V = 0` ?
(ii) What is the impulication of yjis study in day to day life ?

Answer 1

(a) No, not always. This is because, `K` is always positive, so when `V` is equally negative, `E = (K + V)` becomes zero.
(ii) All planet revolving around the sun have negative mechanical energy. It indicates that the planets are bound to revolve around the sun. They are not free to leave their orbit. In day to day life, we find that a person is not free to leave the country, if he owes some amount to income tax (sales tax, etc.) or he has some criminal court cases pending against him.