A flask is closed by a stop valve. The valve allows only those air molecules that are moving faster than a certain speed to move out of the flask and allows only air molecules that are moving slower than that speed to enter the flask from outside. What effect would this filter have on the temperature of the air in the flask.

Two flasks A and B have equal volumes. The molecules in flask A are moving two times faster than the molecules in flask B . The number of molecules in flask A is eight times the number of molecules in flask B . Which of the following is true about the number of collisions with the walls?

A solid body moves through air, at very high speed V faster than the velocity of molecules Show that the drag force on the body is proportional to AV^(2) where A is the frontal area of the body.

A flask has 10 molecules out of which four molecules are moving at 7 ms^(-1) and the remaining ones are moving at same speed of X ms^(-1) . If rms of the gas is 5 ms^(-1) , what is X ?

A bullet fired from a gun is more dangerous than an air molecule hitting a person , though both of them have almost the same speed Way ?

When a particle is restricted to move along x-axis between x=0 and x=a , where alpha if of nenometer dimension, its energy can take only certain specific values. The allowed energies of the particle moving in such a restricted region, correspond to the formation of standing waves with nodes at its ends x=0 and x=a . The wavelength of this standing wave is related to the linear momentum p of the particle according to the de Broglie relation. The energy of the particle of mass m is related to its linear momentum as E=(p^2)/(2m) . Thus the energy of the particle can be denoted by a quantum number n taking values 1,2,3, ...( n=1 , called the ground state) corresponding to the number of loops in the standing wave. Use the model described above to answer the following three questions for a particle moving along the line from x=0 to x=alpha . Take h=6.6xx10^(-34)Js and e=1.6xx10^(-19) C Q. The speed of the particle that can take discrete values is proportional to

A 3000 - mL flask is initailly open while in a room containing air at 1.00 atm and 20^(@)C . The flask is the closed and immersed in a bath of boiling water. When the air in the flask has reach thermodynamic equilibrium, the flask is opend and air is allowed to escap.The flask is then closed and cooled back 20^(@)C (A) What is the maximum pressure reached in the flask? (b) How many moles escape when air is released from the flask? (c) What is the final pressure in the flask?

Two flasks X and Y have capacity 1 L and 2 L respectively and each of them contains 1 mole of a gas. The temperature of the flasks are so adjusted that average speed of molecules in X is twice as those in Y. The pressure in flask X would be

A student forgot to add the reaction mixture to the round bottomed open flask at 27^(@) C and put it one the flame After a lapse of time he realized his mistake using a pyrometer he found the temperature of the flask was 477^(@)C What fraction of air would have been expelled out ? .