What is weightlessness?

A person sitting in an artficial satellite feels weightlessness but a person sitting on moon(which is a satellite of earth) feels some weight.Explain.

A body has a sense of weightlessness in a satellite revolving round the earth.Why?

A vessel of uniform cross-section of length 500 cm as shown in figure is divided in two parts by a weightless and frictionless piston one part contains 5 moles of He(g) and other part 2 moles of H_(2)(g) and 4 moles of O_(2)(g) added at the same temperature and pressure in which reaction takes place finally vessel cooled to 300 K and 1 atm. What is the length of He compartment? (Assume volume of piston and vol. of H_(2)O(l) formed are negligible)

What is electrophoresis ? What is its significance ?

What is Cyclosporin A? What is its importance?

Why does a body becomes weightless at the centre of earth ?

The stone of mass 100 g is suspended from the end of a weightless string of length 100 cm and is allowed to swing in a vertical plane.The speed of the mass is 2 m s^-1 when the string makes an angle of 60^@ with the vertical .Calculate the tension in the string at theta = 60^@ .Also,caculate the speed of the stone when it is in the lowest poition. (g=9.8 m s^(-2) ) .

For a closed container containing 100 mol of an ideal gas fitted with movable, frictionless, weightless piston operating such that pressure of gas remain constant at 8.21 atm, which graph repsents correct variation of log V v//s log T where V is in litre and T is in Kelvin ? (R = 0.0821 (atmL)/(molK))