Answer: when the dipole moment and electric field are parallel
Explanation: The formulae that relates the potential energy of a dipole, dipole moment and strength of electric field is given as
u = p * E cosθ
Where, u= dipole potential energy, p = dipole moment, E = strength of electric field.
The expression is at maximum when θ = 0 (cos 0° = 1)
Hence the function for potential energy will be greatest when θ = 0° which implies that the dipole moment and strength of electric field are parallel to each other.
A device that does work with one movement and changes the size or direction of a force is a simple machine.
Answer:
400 W/m^2 and 31℃
Explanation:
The output heat flux q"= 20 W/m^2 (geven)
The output heat flux from.the wall to the air by convection
q"conv = h(ts - t∞)
q"conv = 20(50-30) = 400 W/m^2
Therefor, this case is unsteady and the wall temperature changes with time till the energy balance exist.
ENERGY BALANCE
The input energy must be equal to the output energy for steady state condition. If not the state will be unstaidy or transient.
2. Its noticed that the output heat flux is not that the I put heat flux, therefore the wall tempers will be decreased till the output heat flux is reduced to the value of the given input heat flux
T steady = T∞ +q"/h
= 30 + 20/20 = 31℃
