The Hubble Space Telescope is in the orbit around the earth at a height of $560 \mathrm{km}$ above the earth's surface Calculate the Hubble's speed.

$\left[\mathrm{G}=6.67 {\mathrm{m}}^3{\mathrm{kg}}^{-1}{\mathrm{s}}^{-2}\right]$

In a servicing mission, a space shuttle spotted the Hubble telescope a distance of $10 \mathrm{km}$. Estimate how long it took the shuttle to catch up with the Hubble, assuming that the Shuttle was moving in a circular orbit just $500 \mathrm{m}$ below Hubble's orbit of $560 \mathrm{km}$.

$\left[\mathrm{G}=6.67\times {10}^{-11}{\mathrm{m}}^3{\mathrm{kg}}^{-1}{\mathrm{s}}^{-2}\right]$

A child is sitting at the edge of a merry-go-round.The arrow shows the velocity of the child.At the instant shown, he releases the ball on to the ground.Which is the path of the ball according to a stationary observer on the ground ?

In which of the following examples of circular motion is the centripetal acceleration experienced by the object largest? In each case, the arrows represent the speed.

A horizontal disk rotates about a vertical axis through the center of the disc. Two particles X and Y are placed on the disc. The particles do not move relative to the disc. Which of the following is correct for angular speed $\omega$ and linear speed $v$ of X and Y?

In the diagram shown below the ratio of the distance of Y to X is $2$. What is the ratio of acceleration on Y to that of X?

A particle of mass $m$ moves with speed $v$ along a hill that may be assumed to be part of the circle of radius $r$. What is the reaction force on the particle at the highest point of the hill?