Answer: touch the pan to the burner
Explanation:
There are three modes of heat transfer:
conduction, convection and radiation.
For conduction, the heat transfers from a hot object to a cold object when the two are in contact.
For convection there is bulk motion of fluid occurs which transfers the heat.
For heat transfer by radiation, medium is not required.
Thus, to demonstrate conduction between pan and burner, the pan must touch the burner.
Answer:

Explanation:
Given:
- mass of steam,

- temperature of steam,

- temperature of resultant water,

We have,
- latent heat of vapourization of water,

- specific heat capacity of water,

<em>When we cool the steam of 100°C then firstly it loses its latent heat to convert into water of 100°C and the further cools the water.</em>
<u>Now the heat removed from steam to achieve the final state of water:</u>




Answer:

Explanation:
Givens



The frequency is defined by

Where
is the speed of the wave in the string and
is its wave length.
The wave length is defined as 
Now, to find the speed, we need the tension of the wire and its linear mass density

Where
and the tension is defined as 
Replacing this value, the speed is

Then, we replace the speed and the wave length in the first equation

Therefore, the frequency is 
Answer:True
Explanation: The mechanical waves need a medium through which to transport energy because the perturbation travels inside of the medium so it needs molecules that connect elastically the displacement of the wave. For example the sound mainly uses the air molecules to transport the energy also the sound can be traveled in solid materials like metal rods.