Gravitation

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- Orbital speed of the satellite v_o= $\sqrt[]{\frac{GM}{R}}$

KE of the satellite of mass m, E_k = 1/2mv_o²= Gmm/2R              

So kinetic energy is inversely proportion

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- Let M be the mass and R be the radius of sphere . an object of mass m be placed at the mid point P of the line joining their centres

Force F₁=F₂=GMm/ (5R)²

If we displace it through x distance

New force towards sphe

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation-Every day the earth advances in the orbit by approximately 1⁰. Then it will have to rotate by 361⁰ to have the sun at zenith point again. So 361⁰ corresponds to 24h

So 1^o corresponds to 24/361= 0.066h=3.99 min =4mi

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- Angle between the equatorial plane and orbital plane of a polar satellite is 90⁰ and angle between equatorial plane and orbital plane of a geostationary satellite is 0⁰.

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- Phelion is the location of the earth where it is the greatest distance from the sun and perihelion is the location of the earth where it is the nearest to the sun

The areal velocity (1/2 rv) of the earth around th

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- As density of the shell is constant

So mass of shell = density (volume)

= $\rho \left(\frac{4}{3}\pi R^3\right)=M$

If we consider shell is uniform so F=gravitational force =GMm/r²

F=0 for r

= GM/r² for r>R

Variation of f verses r

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- Inside a small spaceship orbiting around the earth, the value of acceleration due to gravity can be calculated as constant and hence astronaut feels weightlessness.

If the space station orbiting around the earth h

Explanation- A body can be shielded from the gravitational influence of nearby matter because gravitational force between two point mass bodies is independent of the intervening medium. we cannot shield a body from gravi

This is a  Short Answer Type Questions as classified in NCERT Exemplar
Explanation- Yes, a body can have inertia but no weight. When we taken body to the centre of earth its has some inertia but no weight .

This is a  Short Answer Type Questions as classified in NCERT Exemplar

Explanation- Gravitational forces acting between two point masses m₁ and m₂, F= Gm₁m₂/r² is independent of nature between them. So the gravitational force will remain unaffected when dipped in water.