A thin rod of length L is bent to form a semicircle. The mass of the rod is M. The gravitational potential at the centre of the circle is :
1.
2.
3.
4.
Kepler's second law regarding constancy of the areal velocity of a planet is a consequence of the law of conservation of:
1. Energy
2. Linear momentum
3. Angular momentum
4. Mass
A projectile fired vertically upwards with a speed v escapes from the earth. If it is to be fired at 45 to the horizontal, what should be its speed so that it escapes from the earth?
1. v
2.
3.
4. 2v
The satellite of mass m orbiting around the earth in a circular orbit with a velocity v. The total energy will be:
1.
2.
3.
4.
If \(A\) is the areal velocity of a planet of mass \(M,\) then its angular momentum is:
1. | \(\frac{M}{A}\) | 2. | \(2MA\) |
3. | \(A^2M\) | 4. | \(AM^2\) |
The gravitational potential difference between the surface of a planet and 10 m above is 5 J/kg. If the gravitational field is supposed to be uniform, the work done in moving a 2 kg mass from the surface of the planet to a height of 8 m is
1. 2J
2. 4J
3. 6J
4. 8J
A satellite is moving very close to a planet of density \(\rho.\) The time period of the satellite is:
1. \(\sqrt{\frac{3 \pi}{ρG}}\)
2. \(\left(\frac{3 \pi}{ρG}\right)^{3 / 2}\)
3. \(\sqrt{\frac{3 \pi}{2 ρG}}\)
4. \(\left(\frac{3 \pi}{2 ρG}\right)^{3 / 2}\)
Weightlessness experienced while orbiting the earth in a space-ship is the result of:
1. Inertia
2. Acceleration
3. Zero gravity
4. Freefall towards the earth
The escape velocity from the earth is about 11 km/second. The escape velocity from a planet having twice the radius and the same mean density as the earth is
1. 22 km/sec
2. 11 km/sec
3. 5.5 km/sec
4. 15.5 km/sec
If g is the acceleration due to gravity at the earth's surface and r is the radius of the earth, the escape velocity for the body to escape out of the earth's gravitational field is:
1. gr
2.
3. g/r
4. r/g