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Use the idea of a thermos flask to explain conduction, convection and radiation. Comment also how a thermos flask can reduce heat loss.

Conduction is the transfer of heat caused by the collision of particles inside a substance and between substances. In order to reduce heat loss, some thermos flasks have a vacuum between the container of the...
FR
Answered by Felipe R. • Physics tutor
13424 Views

Why does light change direction when it hits a surface with a different refractive index?

The path upon which light propagates is determined by Fermat's Principle. This says that light will always travel along the path of least time. Now, we often think of the speed of light as a constant, but th...
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Answered by Ben G. • Physics tutor
2961 Views

In the photoelectric effect, why is the kinetic energy of the electrons independent of the intensity of light?

In our situation, the stopping potential doesn’t let any electron to pass. When we increase the frequency of incident light, the electrons get more energy. We know it from equation E=hf. When electrons gain ...
RK
Answered by Rafal K. • Physics tutor
9505 Views

Suggest which particles will be emitted as K-40 decays to Ca-39:

As the proton number increases by 1 from 19(K) to 20(Ca), the process of decay must be beta minus in order to conserve charge. This means that an electron (or beta plus particle) will be emitted along with a...
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Answered by Luke A. • Physics tutor
2236 Views

a solar cell of area 2m^2 has maximum a power output per unit area of 20W/m^2 . if four solar cells are used together at once, how much energy is release in 2 mins at max power output?

max output of 1 cell = 20x2= 40w , so four cells gives 4x40 = 160w so if it gives 160 joules a second then in 2 mins it will put out 160 x (2x60) = 19200 joules
MB
Answered by Merlin B. • Physics tutor
2196 Views