Give scientific reasons.
Even though the magnitude of action force and reaction force are equal and their directions are opposite, their effects do not get cancelled.

Give scientific reasons.

It is easier to stop a tennis ball as compared to a cricket ball, when both are travelling with the same velocity.

Give scientific reasons.

The velocity of an object at rest is considered to be uniform.

Take $5$ examples from your surroundings and give explanation based on Newton's laws of motion.

An object moves $18 \mathrm{m}$ in the first $3 \mathrm{s}$, $22 \mathrm{m}$ in the next $3 \mathrm{s}$ and $14 \mathrm{m}$ in the last $3 \mathrm{s}$. What is its average speed?

An object of mass $16 \mathrm{kg}$ is moving with an acceleration of $3 \mathrm{m} {\mathrm{s}}^{-2}$. Calculate the applied force. If the same force is applied on an object of mass $24 \mathrm{kg}$, how much will be the acceleration?

A bullet having a mass of $10 \mathrm{g}$ and moving with a speed of $1.5 \mathrm{m} {\mathrm{s}}^{-2}$, penetrates a thick wooden plank of mass $90 \mathrm{g}$. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.

A person swims $100 \mathrm{m}$ in the first $40 \mathrm{s}$, $80 \mathrm{m}$ in the next $40 \mathrm{s}$, and $45 \mathrm{m}$ the last $20 \mathrm{s}$. What is the average speed?