Physics Form 4 Chapter 3 Revision

Which of the following statements explain Newton’s Universal Law of Gravitation? I The gravitational force is inversely proportional to the square of the distance between the centre of two bodies. II The gravitational force can be attractive force or repulsive force. III The gravitational force is directly proportional to the product of the masses of the two bodies.

• I and II only

• I and III only

• II and III only

• I, II and III

Graph shows relationship between gravitational force and mass for objects near to earth surface. Gradient of Graph represent

(Daya Graviti= Gravitational Force

Jisim = Mass)

• Acceleration due to gravitational Force

• Universal Gravitational Constant

• Object Weight

• Object momentum

A satellite is placed in a fixed orbit and orbits the earth. The satellite remains in its orbit and does not drift away into space because the satellite

• experiences zero weight

• moves in vacuum

• moves in high speed

• is always being pulled by the gravitational force of Earth

The diagram below shows a planet of mass m, moving in a circular orbit of radius r around the Sun of mass M. The planet takes Orbital Period T to complete one revolution. Which of the following shows the correct relationship between T and m, M, r?

• 0.15 hour

• 1.53 hour

• 15.3 hour

• 153 hour

A stone is tied to the end of a rope and rotated to form a circle as in the figure. When the rotation of the stone reaches 0, the stone is released from the bond. In which direction will the stone continue to move?

• P

• Q

• R

• S

Which of the following statements is not true about geostationary satellites?

• It orbits the earth in the direction of the Earth’s rotation

• The period of its orbit is equal to the period of rotation of the earth

• Its orbit is centered on the equator

• It rotates on its axis with a period equal to that of the earth’s rotation period

A satellite is always on the surface of the earth in the same place throughout the year. What is the length of time for the satellite to move in its orbit?

• 3 hours

• 24 hours

• 100 days

• 365 days