Advertisements
Advertisements
प्रश्न
What do you mean by a gravitational constant?
Advertisements
उत्तर
- From Newton’s law of gravitation,
F = G`("m"_1"m"_2)/"r"^2`
where, G = constant called universal gravitational constant. Its value is 6.67 × 10-11 N m2/kg2. - G = `"Fr"^2/("m"_1"m"_2)`
If m1 = m2 = 1 kg, r = 1 m then F = G.
Hence, the universal gravitational constant is the force of gravitation between two particles of unit mass separated by unit distance.
APPEARS IN
संबंधित प्रश्न
How does the force of gravitation between two objects change when the distance between them is reduced to half?
What is the magnitude of the gravitational force between the earth and a 1 kg object on its surface? (Mass of the earth is 6 × 1024 kg and radius of the earth is 6.4 × 106 m).
The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with a force that is greater or smaller or the same as the force with which the moon attracts the earth? Why?
What happens to the force between two objects, if the distance between the objects is doubled and tripled?
What happens to the force between two objects, if the masses of both objects are doubled?
How will you ‘weigh the sun’, that is estimate its mass? The mean orbital radius of the earth around the sun is 1.5 × 108 km.
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 ?
Let V and E be the gravitational potential and gravitational field at a distance r from the centre of a uniform spherical shell. Consider the following two statements :
(A) The plot of V against r is discontinuous.
(B) The plot of E against r is discontinuous.
Three uniform spheres each having a mass M and radius a are kept in such a way that each touches the other two. Find the magnitude of the gravitational force on any of the spheres due to the other two.
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.
A solid sphere of mass m and radius r is placed inside a hollow thin spherical shell of mass M and radius R as shown in the following figure . A particle of mass m' is placed on the line joining the two centres at a distance x from the point of contact of the sphere and the shell. Find the magnitude of the resultant gravitational force on this particle due to the sphere and the shell if (a) r < x < 2r, (b) 2r < x < 2R and (c) x > 2R.
Write an expression for the gravitational force of attraction between two bodies of masses m1 and m2 separated by a distance r.
All objects in the universe attract each other along the line joining their________.
Is the law of gravitation applicable in case of the sun and the moon?
State the law of gravitation. Why is it called universal?
What is the difference between gravity and gravitation?
Is there a gravitational attraction between you and the book? Explain.
Answer the following question.
State Newton’s law of gravitation and express it in vector form.
Mahendra and Virat are sitting at a distance of 1m from each other. Their masses are 75 kg and 80 kg respectively. What is the gravitational force between them? (G = 6.67 × 10−11 Nm2/kg2)
For the weight of body of mass 5 kg to be zero on equator of the earth, angular velocity of the earth must be (The radius of earth = 6400 km, acceleration due to gravity = 10 m/s2).
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.
Shown are several curves (Figure). Explain with reason, which ones amongst them can be possible trajectories traced by a projectile (neglect air friction).
Complete the chart below.
| F(N) | M1(kg) | M2(kg) | D(m) |
| (a) | 50 | 84 | 02 |
| 16 × 109 | 1.63 × 1022 | (b) | 34 |
Write the answer of the question with reference to laws of gravitation.
Write the value of the universal gravitational constant.
Answer the following questions in reference to the figure below:
- Which relation is shown in the figure?
- What will happen if the mass of one of the objects is doubled?
Four identical particles of equal masses 1 kg made to move along the circumference of a circle of radius 1 m under the action of their own mutual gravitational attraction. The speed of each particle will be ______.
If the mass of one object is doubled and distance remains the same, the gravitational force will ______.
For an object outside a uniform solid sphere, from where is the sphere's mass considered to act?
