Why is it easier to balance a bicycle in motion?

Why is it easier to start a car engine on a warm day than on a chilly day ?

When pedalling is stopped the velocity of a bicyle in motion gradually decreases. Why?

It is easier to catch, a table tennis ball than a cricket ball even when both are moving with same velocity. Why?

It is easier to revolve a stone by attaching it to a shorter string rather than- to a longer one. Why?

Give two example of periodic motion.

What is a wave motion?

Define rest and motion

Write Kepler's laws on planetary motion.

It is easier to maintain the motion of a body than to start it. Why?

Why should the balance point be obtained in the middle of the wire of a metre bridge?