Physics Questions

Radio waves have much longer wavelengths and lower frequencies than do visible light waves. In contrast, X-rays have much shorter wavelengths and higher frequencies. 

Ultraviolet Light (UV). part of the electromagnetic spectrum that consists of waves with frequencies higher than those of visible light and lower than those of x-rays.

A star is a self luminous astronomical object and shines due to internal radiation from the enrgy sources. All stars are held together by their own gravity called Gravitational force.

There are approximately 6 trillion miles in a light-year, so the distance we need to go is 6 trillion miles / light-year times. 4 light-years is equal to 24 trillion miles. So, this whole would take 1.2 billion hours. There are 24 hours a day and 365.25 days per year, so this time in years is 137 thousand years.

Processes that require or give off heat will be limited to changes of state, known as phase changes, and changes in chemical constitution, or chemical reactions. Changes of state involve a solid melting, a liquid freezing, a liquid boiling or a gas condensing.

An exothermic process is one that gives off heat, which is transferred to the surroundings. An endothermic process is a reaction which heat has to be supplied to the system from the surroundings.

Here in all the given options, heat is taken away from them to change there phase. 

Liquid to Solid --- Freezing

Gas to Liquid --- Condensation

Gas to Solid --- Deposition 

are all examples of exothermic processes.

The flow of thermal energy due to differences in their temperatures is called Heat.

Pitot tube is used to measure stagnation pressure.