Which rays are used in a TV remote?

Why is efficiency of a machine is always less than 100% ?

Explain why a piece of solid steel weighing a few grams sinks in water but a ship weighing thousands of kilograms can float.

How come in free fall you feel weightless even though gravity is pulling down on you?

When I look at the tyres of a moving vehicle in a movie the look as if they are moving in the opposite direction. How can we explain this phenomenon/effect?

A ball ? is always in neutral equilibrium. Explain.

Distingush between Bernoulli’s effect and Bernoulli’s principle.

what is the difference between limiting and dynamic forces of friction?