PART - 2 CH - 11 Thermodynamics — Physics STD 11 Science — Question

Can the potential energy in a simple harmonic motion be negative? Will it be so if we choose zero potential energy at some point other than the mean position?

Answer the following questions based on the P-T phase diagram of carbon dioxide

1. At what temperature and pressure can the solid, liquid and vapour phases of CO₂ co-exist in equilibrium ?
2. What is the effect of decrease of pressure on the fusion and boiling point of CO₂?
3. What are the critical temperature and pressure for CO₂? What is their significance?
4. Is CO₂ solid, liquid or gas at (a) –70 °C under 1 atm, (b) –60 °C under 10 atm, 15 °C under 56 atm?

A man is standing on top of a building 100m high. He throws two balls vertically, one at t = 0 and other after a time interval (less than 2 seconds). The later ball is thrown at a velocity of half the first. The vertical gap between first and second ball is +15m at t = 2s. The gap is found to remain constant. Calculate the velocity with which the balls were thrown and the exact time interval between their throw.

A laser light is focused by a converging lens. Will there be a significant chromatic aberration?

A car moving at a speed of 10m/s is accelerated at the rate of 2m/s². Find out the velocity after 6 sec.

Two masses in the ratio 1 : 2 are thrown vertically up with the same speed. What is the effect on the time by the mass?

Estimate the mean free path for a water molecule in water vapour at 373 K. Use information from Exercises 12.1 and Eq. (12.41) above.

A particle is in linear simple harmonic motion between two points, A and B, 10cm apart. Take the direction from A to B as the positive direction and give the signs of velocity, acceleration and force on the particle when it is:

At 2cm away from B going towards A.

What is the initial phase angle of a body starting simple hormonic motion from the terminal end?

Is coefficient of performance of a refrigerator constant?