Advertisements
Advertisements
प्रश्न
Give scientific reasons for the following:
Newton's gravitational law is the universal law of gravitation.
Advertisements
उत्तर
Newton's gravitational law is applicable throughout the universe and to all particles. Hence, it is called the universal law of gravitation.
APPEARS IN
संबंधित प्रश्न
Choose the correct alternative:
Acceleration due to gravity is independent of mass of the earth/mass of the body.
Choose the correct answer from among the given ones:
For the problem 8.10, the direction of the gravitational intensity at an arbitrary point P is indicated by the arrow (i) d, (ii) e, (iii) f, (iv) g.
A rocket is fired from the earth towards the sun. At what distance from the earth’s centre is the gravitational force on the rocket zero? Mass of the sun = 2 ×1030 kg, mass of the earth = 6 × 1024 kg. Neglect the effect of other planets etc. (orbital radius = 1.5 × 1011 m).
Can we apply Newton’s third law to the gravitational force ? Explain your answer.
Derive an expression for the gravitational field due to a uniform rod of length L and mass M at a point on its perpendicular bisector at a distance d from the centre.
Two concentric spherical shells have masses M1, M2 and radii R1, R2 (R1 < R2). What is the force exerted by this system on a particle of mass m1 if it is placed at a distance (R1+ R2)/2 from the centre?
State whether the gravitational force between two masses is attractive or repulsive ?
Multiple Choice Question. Select the correct option.
The mass of earth is 6 × 1024 kg and radius of earth is 6.4 × 106 m. The magnitude of force between the mass of 1 kg and the earth is:
The force of attraction between any two material objects is called __________.
A force can produce ________, In an object at rest. It can __________ an object and change its __________ of motion.
What does a force do in the following case?
You twist a piece of rubber.
What does a force do in the following case?
You apply brakes to a running car.
What does a force do in the following case?
You catch a kicked ball.
Name and state the action and reaction in the following case:
A person walking on the ground.
Name and state the action and reaction in the following case:
Hammering a nail.
Explain the difference between g and G.
The distance-time values for an object moving along straight line are given below:
| Time (s) | Distance (m) |
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 27 |
Different points in earth are at slightly different distances from the sun and hence experience different forces due to gravitation. For a rigid body, we know that if various forces act at various points in it, the resultant motion is as if a net force acts on the c.m. (centre of mass) causing translation and a net torque at the c.m. causing rotation around an axis through the c.m. For the earth-sun system (approximating the earth as a uniform density sphere).
Particles of masses 2M, m and M are respectively at points A, B and C with AB = ½ (BC). m is much-much smaller than M and at time t = 0, they are all at rest (Figure). At subsequent times before any collision takes place ______.
Six point masses of mass m each are at the vertices of a regular hexagon of side l. Calculate the force on any of the masses.
