The energy flow in an ecosystem is related with the second law of thermodynamics.

When a spring is compressed and then released the potential energy is converted into kinetic energy.

This is due to law of conservation of _____

A simple pendulum, while oscillation, rises to a maximum vertical height $5 \mathrm{cm}$from its rest position when it reaches to one side on its extreme position. If mass of bob of simple pendulum is $500 \mathrm{g}$and $g=10 {\mathrm{ms}}^{-2}$, find the velocity of bob at its resting position. State the assumption made in your calculation.

What do you mean by degradation of energy ? Explain it by taking one example from your daily life.

Divya always switched off unwanted lights, fans and electric gadgets when not in use. Comparatively her electricity bill cut down to half:

$\left(c\right)$ What values does Divya show?

Energy can neither be created nor destroyed. Then why is there so much fuss about every crisis?

A stone of mass $500 \mathrm{g}$is thrown vertically upwards with a velocity of $15 \mathrm{m} {\mathrm{s}}^{-1}$. Calculate the total energy at its halfway point.