Magnitude of potential energy (U) and time period (T) of a satellite are related to each other as:
1.
2.
3.
4.
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
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 point P lies on the axis of a ring of mass M and radius 'a' at a distance 'a' from its centre C. A small particle starts from P and reaches C under gravitational attraction. Its speed at C will be :
1.
2.
3.
4. zero
Two bodies of masses m and 4m are placed at a distance r. The gravitational potential at a point on the line joining them where the gravitational field is zero is
1.
2.
3.
4. 0
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. | \(AM^2\) |
In planetary motion, the areal velocity of the position vector of a planet depends on the angular velocity () and the distance of the planet from the sun (r). The correct relation for areal velocity is:
1.
2.
3.
4.
A planet is moving in an elliptical orbit. If T, V, E, and L stand, respectively, for its kinetic energy, gravitational potential energy, total energy and angular momentum about the center of the orbit, then:
1. | T is conserved |
2. | V is always positive |
3. | E is always negative |
4. | the magnitude of L is conserved but its direction changes continuously |
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 projectile is fired upwards from the surface of the earth with a velocity where is the escape velocity and k < 1. If r is the maximum distance from the center of the earth to which it rises and R is the radius of the earth, then r equals:
1. \(\frac{R}{k^2}\)
2. \(\frac{R}{1-k^2}\)
3. \(\frac{2R}{1-k^2}\)
4. \(\frac{2R}{1+k^2}\)