Answer:
C or 3
Explanation:
A: no they are called sources of sound. A is incorrect.
B: It does. Many people attest to this. But this is not a property of physics.
C: A media is required is the correct answer.
D: Dogs might. In general we don't.
I would pick C
Answer:
0.0321 g
Explanation:
Let helium specific heat 
Assuming no energy is lost in the process, by the law of energy conservation we can state that the 20J work done is from the heat transfer to heat it up from 273K to 393K, which is a difference of ΔT = 393 - 273 = 120 K. We have the following heat transfer equation:

where
is the mass of helium, which we are looking for:

The magnet will be a useful tool to pick the paper clips because the magnet can attract the paper clips.
<h3>
Attraction of magnets</h3>
The like poles of magnets repel while unlike poles of magnets attracts. Magnets attracts irons or metallic materials.
The paper clips are mettalic or made of iron and hence the magnet will attract them.
There we can conclude that the magnet will be a useful tool to pick the paper clips because the magnet can attract the paper clips and will help to gather them together for easy picking.
Learn more about magnets here: brainly.com/question/14997726
8.16m is the required height, a 5kg stone need to be raised.
One sort of potential energy is gravitational potential energy, which is equal to the product of the object's mass (m), the gravitational acceleration (g), and the object's height (h) as measured in relation to the ground's surface (the body).
We obtain the formula by considering the work done in raising a mass m through a height h.
Work in elevating mass m through height h is equal to force times distance.
The force must be greater than the mass m's weight, hence F = mg.
Work done = mgh = gravitational potential energy
Energy = Mass of the object × gravitational acceleration × height.
Mass of the stone = 5kg
Equating ;
∴ 400 J = 5 kg × 9.8 m/s² × height
Height = 8.16 m
Therefore, 8.16m is the required height.
Learn more about energy here:
brainly.com/question/1242059
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Answer:
heat is the transfer of thermal energy from a system to its surroundings or from ... It is very important to know that, in science, heat and temperature are not the same thing. ... Have you noticed that when you put a cold, metal teaspoon into your hot cup of ... AIM: To investigate which materials are the best conductors of heat.
Explanation: