FWS asked in Science & MathematicsPhysics · 3 months ago

# How to do for this two questions?

1.Explain in your words about how gravitational force works between two isolated objects and use this understanding to explain how a satellite can remain at the same place above the surface of the rotating earth.

2. In an experiment to study Hooke's law for solid material, the extension for three different wires A, B and C were obtained for various applied force as shown in TABLE Q3b.

a.Consider all the extensions were within the elastic limit. Draw graph of extension against force for each wire and use it to identify which of the wires requires the most work done to extend to 3.8 mm.

b.Determine the elastic modulus of each wire and arrange them according to their stiffnesses.

Relevance
• 3 months ago

The gravitational force on a body is certain type of pull that is directed towards a second body. It is of attractive nature. The gravitational force is directed along centre of both the bodies. It is given as : {GM1M2}/{R^2}

G is the graviational constant whose value is 6.67 × 10-11 Newtons kg-2 m2.

M1, M2 are masses of objects, R is seperation between centre of both the bodies.

The Earth exerts a gravitational towards each body given as F = mg

where m is the mass of object, g = gravitational attraction due to Earth

g is given as GM R2 where M is mass of Earth. Like earth attracts every body, in reaction every body also attracts earth. More massive body exerts more gravitational force on other body. Like Earth and other heavenly bodies, each objects attracts other object by gravitational force whose value is given according to above formula and is directed towards their centres.

how can a satellite remain at same place above the surface of rotating Earth?

The gravitational force between Earth and satellite system is given as. GMMS Fg = H2

where Ms is mass of satellite, H is seperation from centre of Earth and satellite.

The satellite is launched with such velocity that they stay at a particular height (H) and keep on orbitting Earth. At a height H -

Fg = {GMeMs}/{H2} = Fc = MsV^2/H^2

the centrifugal force balances the gravitational force and satellite remains at the same place above the surface of rotating Earth.