Answer:
A = 2.1 × 10^(-4) m²
Explanation:
We are given;
Temperature; T = 2450 K
Emissivity; ε = 0.35
Bulb rating; H = 150 W
To calculate the surface area, we will use the formula;
H = AεσT⁴
Where σ is stephan boltzman constant with a value of 5.66 × 10^(−8) W/m²⋅K⁴
Making A the subject of the formula, we have;
A = H/εσT⁴
Plugging in the relevant values gives;
A = 150/(0.35 × 5.66 × 10^(−8) × 2450⁴)
A = 2.1 × 10^(-4) m²
Sublimation is the transition of a substance directly from the solid state to the gas state; therefore:
c. solid to a gas
Answer:
Also as we can see the equation that heat flux directly depends on the temperature gradient so more is the temperature gradient then more will be the heat flux.
For positive temperature gradient the heat will flow outwards while for negative temperature gradient the heat will flow inwards
Explanation:
As we know that heat flux is given by the formula
here we know that
K = thermal conductivity
= temperature gradient
now we know that
also we know that
K = 1.7 W/mK
now we have
so temperature gradient is given as
also in other unit it will be same
Also as we can see the equation that heat flux directly depends on the temperature gradient so more is the temperature gradient then more will be the heat flux.
For positive temperature gradient the heat will flow outwards while for negative temperature gradient the heat will flow inwards
The correct answer is:
<span>A. electron attraction between electron and nucleus = centripetal force of the orbiting electron
In fact, Bohr model depicts the atom as a nucleus surrounded by electrons in circular orbit around it, similar to the planets around the Sun. The centripetal force that keeps the electrons in circular motion around the nucles is provided by the electrostatic force between the electrons and the nucleus, so option A is the correct one.</span>
