A small coin is placed on a record rotating at $33\frac{1}{3} \mathrm{rev} {\min }^{-1}$. The coin does not slip on the record. Where does it get the required centripetal force from?

A bird while flying takes a left turn, where does it get the centripetal force from?

A smooth block loosely fits in a circular tube placed on a horizontal surface. The block moves in uniform circular motion along the tube. Which wall (inner or outer) will exert a non-zero normal contact force on the block?

Consider the circular motion of the earth around the sun. Which of the following statements is more appropriate?

(a) Gravitational attraction of the sun on the earth is equal to the centripetal force.
(b) Gravitational attraction of the sun on the earth is the centripetal force.