1. | Kepler's law of areas still holds. |
2. | Kepler's law of period still holds. |
3. | Kepler's law of areas and period still hold. |
4. | Neither the law of areas nor the law of period still hold. |
The distance of a planet from the sun is \(5\) times the distance between the earth and the sun. The time period of the planet is:
1. | \(5^{3/2}\) years | 2. | \(5^{2/3}\) years |
3. | \(5^{1/3}\) years | 4. | \(5^{1/2}\) years |
Two satellites \(A\) and \(B\) go around the earth in circular orbits at heights of \(R_A ~\text{and}~R_B\) respectively from the surface of the earth. Assuming earth to be a uniform sphere of radius \(R_e\), the ratio of the magnitudes of their orbital velocities is:
1. \(\sqrt{\frac{R_{B}}{R_{A}}}\)
2. \(\frac{R_{B} + R_{e}}{R_{A} + R_{e}}\)
3. \(\sqrt{\frac{R_{B} + R_{e}}{R_{A} + R_{e}}}\)
4. \(\left(\frac{R_{A}}{R_{B}}\right)^{2}\)
1. | \(16L\) | 2. | \(64L\) |
3. | \(L \over 4\) | 4. | \(4L\) |
A body of mass \(m\) kg starts falling from a point \(2R\) above the Earth’s surface. Its kinetic energy when it has fallen to a point \(R\) above the Earth’s surface, is:
[\(R\text-\) Radius of Earth, \(M\text-\) Mass of Earth, \(G\text-\) Gravitational Constant]
1. \(\frac{1}{2} \frac{G M m}{R}\)
2. \(\frac{1}{6} \frac{G M m}{R}\)
3. \(\frac{2}{3} \frac{G M m}{R}\)
4. \(\frac{1}{3} \frac{G M m}{R}\)
A body is projected vertically upwards from the surface of a planet of radius \(R\) with a velocity equal to half the escape velocity for that planet. The maximum height attained by the body is:
1. \(\frac{R}{3}\)
2. \(\frac{R}{2}\)
3. \(\frac{R}{4}\)
4. \(\frac{R}{5}\)
A satellite is launched into a circular orbit of radius \(R\) around the Earth while a second satellite is launched into an orbit of radius \(1.02~\text{R}\). The percentage difference in the time periods of the two satellites is:
1. | \(0.7\) | 2. | \(1.0\) |
3. | \(1.5\) | 4. | \(3\) |
If the gravitational force between two objects were proportional to \(\frac{1}{R}\) (and not as\(\frac{1}{R^2}\)) where \(R\) is the separation between them, then a particle in circular orbit under such a force would have its orbital speed \(v\) proportional to:
1. \(\frac{1}{R^2}\)
2. \(R^{0}\)
3. \(R^{1}\)
4. \(\frac{1}{R}\)
If the acceleration due to gravity at a height \(1\) km above the earth is similar to a depth \(d\) below the surface of the earth, then:
1. \(d= 0.5\) km
2. \(d=1\) km
3. \(d=1.5\) km
4. \(d=2\) km
Two astronauts are floating in a gravitational free space after having lost contact with their spaceship. The two will:
1. | keep floating at the same distance between them |
2. | move towards each other |
3. | move away from each other |
4. | will become stationary |