Thermodynamics — Physics STD 11 Science — Question

A cloudy night is hotter than a clear sky night. Why?

Raindrops of radius 1mm and mass 4mg are falling with a speed of 30m/s on the head of a bald person. The drops splash on the head and come to rest. Assuming equivalently that the drops cover a distance equal to their radii on the head, estimate the force exerted by each drop on the head.

Which quantity does not change during change of state?

A steel plate of face area 4cm² and thickness 0.5cm is fixed rigidly at the lower surface. A tangential force of 10N is applied on the upper surface. Find the lateral displacement of the upper surface with respect to the lower surface. Rigidity modulus of steel = 8.4 × 10¹⁰N/m².

If the density of a gas is kept constant but the root mean square velocity of the gas molecules is doubled, then how much will the pressure of the gas increase?

A cricketer pulls his hands backward, holding a catch. Explain.

What will be the ratio of root mean square forces of hydrogen and oxygen molecules at the same temperature?

What will be the time period of oscillation, if the length of a second pendulum is one third?

When a bottle of cold carbonated drink is opened, a slight fog is formed around the opening, why?

A tunning frok produce resonance in a closed tube, but it can't produce resonance in an open tube of the same length. why?