Mechanical Properties of Fluids — Physics STD 11 Science — Question

If no external torque act on a body, will its angular velocity remain conserved?

Person sitting in a moving bus in uniform motion fall forward when sudden break is applied. It is due to ________.

In a game of tug of war, one team is slowly giving way to the other. Which team is doing positive work and which team negative?

Answer the following: An artificial satellite orbiting the earth in very thin atmosphere loses its energy gradually due to dissipation against atmospheric resistance, however small. Why then does its speed increase progressively as it comes closer and closer to the earth?

A lift is accelerated upward. Will the apparent weight of a person inside the lift increases, decreases or remains the same relative to its real weight? If the lift is going with uniform speed, then?

Explain this statement clearly: “To call a dimensional quantity ‘large’ or ‘small’ is meaningless without specifying a standard for comparison”. In view of this, reframe the following statements wherever necessary:

1. Atoms are very small objects
2. A jet plane moves with great speed
3. The mass of Jupiter is very large
4. The air inside this room contains a large number of molecules
5. A proton is much more massive than an electron
6. The speed of sound is much smaller than the speed of light.

A one meter long glass tube is open at both ends. One end of the tube is dipped into a mercury cup, the tube is kept vertical and the air is pumped out of the tube by connecting the upper end to a suction pump. Can mercury be pulled up into the pump by this process?

When air is blown in between two balls suspended close to each other, they are attracted towards each other. Give reason.

A comet orbits the sun in a highly elliptical orbit. Does the comet have a constant (a) linear speed, (b) angular speed, (c) angular momentum, (d) kinetic energy, (e) potential energy, (f) total energy throughout its orbit? Neglect any mass loss of the comet when it comes very close to the Sun.

Give an example of a body possessing zero velocity and still accelerating.