Gravitation

Gravitation

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Multiple Choice

Which is stronger, Earth's pull on the Moon or the Moon's pull on Earth?

• Earth pulls harder on the Moon

• Moon pulls harder on Earth

• They pull each other equally

• It depends upon where the Moon is in its orbit at that time

Multiple Choice

Work done in bringing the mass from infinity to a point is always positive.

• True

• False

Multiple Choice

According to Newton's Universal law of gravitation, if the distance between two objects is reduced into half, the force between them is ____.

• Halved

• Stays the same

• Doubled

• Quadrupled

Multiple Choice

The amount of work to bring a mass from a point to infinity is positive.

• True

• False

Multiple Choice

The gravitational field lines on the Earth's surface are said to be radial.

• True

• False

Multiple Choice

Defined as the speed an object must maintain to stay in orbit.

• Escape Velocity

• Cosmic Velocity

• Orbital Velocity

• Second cosmic velocity

Multiple Choice

Which of the following correctly relates the radius R of the circular orbit of a planet round a star to the period T of the orbit?

• $$R^{3\ }\propto T^2$$

• $$R^3\ \propto\ T^3$$

• $$\frac{1}{R^3}\ \propto T^2$$

• $$\frac{1}{R^2}\propto T^3$$

Multiple Choice

Which is the correct equation for escape velocity?

• $$Vescape\ =\ \sqrt{\frac{2GM}{R^2}}$$

• $$Vescape\ =\ \sqrt{\frac{GM}{R}}$$

• $$Vescape\ =\ \sqrt{\frac{GM}{R^2}}$$

• $$Vescape\ =\ \sqrt{\frac{2GM}{R}}$$

Multiple Choice

Which of the following is NOT a correct equation for Gravitational Field Strength (g)?

• $$g\ =\ \frac{Fg}{m}$$

• $$g\ =\frac{GM}{r^2}$$

• $$g\ =\ \frac{GM}{\left(r\ +\ h\right)^2}$$

• $$g\ =\ -\frac{GM}{r}$$

Fill in the Blanks

A uniform sphere which covers a very large distance as compared to its size