Answer : C. Pascal's principle.
Explaination : Pascal's principle (well-known as Pascal's law) states that if a closed container contains a fluid at rest, then a small change in pressure at one side of the fluid is transmitted to each and every part of the fluid and also to the walls of the container without any loss. In a hydraulic lift, we need the same mechanism to work and so we take the help of Pascal's principle.
Hence, the correct option is C. Pascal's principle.
Answer:
Always wear safety goggles when performing an experiment.
Use caution when dropping objects and/or launching them into the air.
Use only the materials that your teacher provides or approves.
Check the soda bottle and its cap for cracks and chips prior to use.
Report all accidents—no matter how big or small—to your teacher.
Answer:
Well I'm going to go with A.
Explanation:
As per the question the mass of the boy is 40 kg.
The boy sits on a chair.
We are asked to calculate the force exerted by the boy on the chair at sea level.
The force exerted by boy on the chair while sitting on it is nothing else except the force of gravity of earth i.e the weight of the body .The direction of that force is vertically downward.
At sea level the acceleration due to gravity g = 9.8 m/s^2
Therefore, the weight of the boy [m is the mass of the body]
we have m = 40 kg.
Therefore, w = 40 kg ×9.8 m/s^2
=392 N kg m/s^2
= 392 N
392 is not an option but I'm guessing you can round down 2 .to option A. 390...?
Answer:

Explanation:
The speed of light through a medium is given by:

where
is the speed of light through vacuum
n is the index of refraction of the material
In this case, diamond has a refractive index of n = 2.4, so the speed of light in diamond is
