The Forces — Physics STD 11 Science — Question

When we stir a liquid vigorously, it becomes warm. Is it a reversible process?

Two bodies A and B at temperatures 327°C and 127°C respectively are placed in an evacuated enclosure maintained at a temperature of 27°C. Compare their rates of cooling.

A uranium reactor develops thermal energy at a rate of 300MW. Calculate the amount of ²³⁵U being consumed every second. Average released per fission is 200MeV.

State law of equi-partition of energy. Use this law to calculate specific heats of monoatomic, diatomic and triatomic gases.

Find an expression for the orbital velocity of a satellite revolving around the earth in a circular orbit at a height h above the surface of earth.

A man of mass 70kg stands on a weighing scale in a lift which is moving.
Downwards with a uniform acceleration of 5ms^-2.

Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity):
The mass of an elephant.

2g of hydrogen is sealed in a vessel of volume 0.02m³ and is maintained at 300K. Calculate the pressure in the vessel.

A solid sphere of mass m and radius r is impure rolling on a horizontal surface. What fraction of total energy of the sphere is:

1. Kinetic energy of rotation?
2. Kinetic energy of translation?

In a HCl molecule, we may treat Cl to be of infinite mass and H alone be oscillating. If the oscillation of HCl molecule shows a frequency of 9 × 10¹³s^-1, deduce the force constant. [Given: Avogadro's number = 6 × 10²⁶ per kg mole.)