Function of insulators is protection against sound or electric current or ,heat based on the type of insulators.
They use in wires (plastic)
Use in making soundproof rooms
Thermal insulators are use in making water bottles. Keep the water warm
Answer:
the correct answer is c, they will accelerate away from each other at different speeds. the 80kg will go faster due to less mass
Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:
Where,
= Wavelength of radiation
= Rydberg's Constant = 10973731.6 m⁻¹
= Higher energy level = 3
= Lower energy level = 2
Putting the values, in above equation, we get:
Now we have to calculate the energy.
where,
h = Planck's constant = 
c = speed of light = 
= wavelength = 
Putting the values, in this formula, we get:
Therefore, the energy of one photon of hydrogen atom is,
Answer:
If one end of a metal bar is heated, the atoms at that end vibrate more than the atoms at the cold end. The vibration spreads along the bar from atom to atom.
Explanation:
The spread of heat in this way is called conduction. Metals are good conductors of heat.
