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).
पर्याय
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 mass of one object is doubled?
Can you think of two particles which do not exert gravitational force on each other?
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?
A body is suspended from a spring balance kept in a satellite. The reading of the balance is W1 when the satellite goes in an orbit of radius R and is W2 when it goes in an orbit of radius 2 −R.
Which of the following quantities remain constant in a planetary motion (consider elliptical orbits) as seen from the sun?
A particle of mass 100 g is kept on the surface of a uniform sphere of mass 10 kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle away from the sphere.
The gravitational field in a region is given by \[E = \left( 2 \overrightarrow{i} + 3 \overrightarrow{j} \right) N {kg}^{- 1}\] . Show that no work is done by the gravitational field when a particle is moved on the line 3y + 2x = 5.
[Hint : If a line y = mx + c makes angle θ with the X-axis, m = tan θ.]
A ball is thrown vertically upwards. It goes to a height 20 m and then returns to the ground. Taking acceleration due to gravity g to be 10 ms-2, find: the initial velocity of the ball.
A ball is thrown vertically upwards. It goes to a height 20 m and then returns to the ground. Taking acceleration due to gravity g to be 10 ms-2 , find :
the final velocity of the ball on reaching the ground .
Who stated the law of gravitation?
A ball is thrown up with a speed of 4.9 ms-1.
Calculate the time it takes to reach this height.
At what height above the earth's surface would the value of acceleration due to gravity be half of what it is on the surface? Take the radius of earth to be R.
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:
Hammering a nail.
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 ________.
Solve the following problem.
Find the gravitational force between the Sun and the Earth.
Given Mass of the Sun = 1.99 × 1030 kg
Mass of the Earth = 5.98 × 1024 kg
The average distance between the Earth and the Sun = 1.5 × 1011 m.
Give the applications of universal law gravitation.
If the mass of one object is doubled and distance remains the same, the gravitational force will ______.
