Advertisements
Advertisements
प्रश्न
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).
विकल्प
the torque is zero.
the torque causes the earth to spin.
the rigid body result is not applicable since the earth is not even approximately a rigid body.
the torque causes the earth to move around the sun.
Advertisements
उत्तर
The torque is zero.
Explanation:
As the earth is revolving around the sun in a circular motion due to gravitational attraction. The force of attraction will be of radial nature i.e., the angle between position vector r and force F is zero. So, torque = |τ| = |r × F| = rFsin0° = 0.
APPEARS IN
संबंधित प्रश्न
What happens to the force between two objects, if the distance between the objects is doubled and tripled?
Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = 6 × 1024 kg and of the Sun = 2 × 1030 kg. The average distance between the two is 1.5 × 1011 m.
The gravitational intensity at the centre of a hemispherical shell of uniform mass density has the direction indicated by the arrow (see Fig 8.12) (i) a, (ii) b, (iii) c, (iv) 0.
State the universal law of gravitation. Name the scientist who gave this law.
Universal law of gravitation states that every object exerts a gravitational force of attraction on every other object. If this is true, why don’t we notice such forces ? Why don’t the two objects in a room move towards each other due to this force ?
At noon, the sun and the earth pull the objects on the earth's surface in opposite directions. At midnight, the sun and the earth pull these objects in same direction. Is the weight of an object, as measured by a spring balance on the earth's surface, more at midnight as compared to its weight at noon?
Two spherical balls of mass 10 kg each are placed 10 cm apart. Find the gravitational force of attraction between them.
Four particles having masses m, 2m, 3m and 4m are placed at the four corners of a square of edge a. Find the gravitational force acting on a particle of mass m placed at 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?
A tunnel is dug along a chord of the earth at a perpendicular distance R/2 from the earth's centre. The wall of the tunnel may be assumed to be frictionless. Find the force exerted by the wall on a particle of mass m when it is at a distance x from the centre of the tunnel.
State whether the gravitational force between two masses is attractive or repulsive ?
What does a force do in the following case?
You twist a piece of rubber.
Gravity is another kind of ________. It exerts all through the ________. The Sun's gravity keeps the ___________ in their orbits. Gravity can only be felt with very large ________.
State Newton's law of gravitation. What is the difference between:
g and G?
To project the rockets which of the following principle(s) is /(are) required?
The gravitational force between a hollow spherical shell (of radius R and uniform density) and a point mass is F. Show the nature of F vs r graph where r is the distance of the point from the centre of the hollow spherical shell of uniform density.
The acceleration of the Moon towards the Earth is approximately ______.
For an object outside a uniform solid sphere, from where is the sphere's mass considered to act?
The gravitational force between two objects acts in which direction?
