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℃
Answer:
I = 0.5 A
Explanation:
Given: P=60 Watts, Voltage supply V = 120 Volts (for primary coil)
Solution:
we have P = V I
⇒ I = P /V = 60 Watts / 120 Volts
I = 0.5 A
The equation you use is Ke = 1/2mv^2. when you plug in the numbers that are given you get Ke= 1/2(4)(2^2) which gives you a Kinetic Energy of 8
I'm not sure about the rest but for question 2:
A theory is an attempt to come up with a big picture of all we know so far. It also drives future research as people do experiments to see if what the theory predicts actually happens. When experiments don’t support the theory, you have to change the theory and try again. That’s how science works. We come up with a “best guess” (theory), and then do research to test it’s accuracy. As we discover contradictions, we adjust the theory to take those into account, and then start testing the validity of the new theory.
The answer is focal point.
The focal length is the distance from the lens (or mirror) to the focal point. The focal point is <span>the point at which rays of light converge.</span>
