Answer: the refraction of light by the atmosphere
Explanation: Refraction is the phenomenon in which there is a change in direction of light passing from one medium to another or from a gradual change in the medium.
Here in case of sunset, the sun rays passes through the varying density of atmosphere because of varying concentrations of dust particles.
Reflection is the phenomenon in which the light bounces back after falling on a surface.
Absorption is the phenomenon in which matter captures the electromagnetic radiations and thus the energy of photons is converted to internal energy of the system.
Answer:
Choice A: approximately
, assuming that the two pistons are connected via some confined liquid to form a simple machine.
Explanation:
Assume that the two pistons are connected via some liquid that is confined. Pressure from the first piston:
.
By Pascal's Principle, because the first piston exerted a pressure of
on the liquid, the liquid will now exert the same amount of pressure on the walls of the container.
Assume that the second piston is part of that wall. The pressure on the second piston will also be
. In other words:
.
To achieve a force of
, the surface area of the second piston should be:
.
Answer:
3.6μF
Explanation:
The charge on the capacitor is defined by the formula
q = CV
because the charge will be conserved
q₁ = C₁V₂
q₂ = C₂V₂ where C₂ V₂ represent the charge on the newly connected capacitor and the voltage drop across the two capacitor will be the same
q = q₁ + q₂ = C₁V₂ + C₂V₂
CV = CV₂ + C₂V₂
CV - CV₂ = C₂V₂
C ( V - V₂) = C₂V₂
C ( V/ V₂ - V₂ /V₂) = C₂
C₂ = 0.9 ( 10 /2) - 1) = 0.9( 5 - 1) = 3.6μF
Answer: If there is a higher friction, the opposition force is higher so that it can reduce our speed. So, a factor that affects friction is the roughness or smoothness of the surface of the object. In comparison of the table with the fabric, the fabric will have a more opposition force. As the surface of the fabric is usually rougher than the surface of a smooth table. As there is more friction on a fabric, we will feel more opposition force on our finger tip.
Hope it helped! :>
Answer:
a) 
b)
parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.
Explanation:
Given:
mass of the bee, 
charge acquired by the bee, 
a.
Electrical field near the earth surface, 
Now the electric force on the bee:
we know:




The weight of the bee:



Therefore the ratio :


b.
The condition for the bee to hang is its weight must get balanced by the electric force acing equally in the opposite direction.
So,



parallel to the earth surface.
- In this case according to the Fleming's left hand rule the direction of movement of bee must be in a direction parallel to the earth surface and perpendicular to the electric field at the same time.