Answer:
solution:
dT/dx =T2-T1/L
&
q_x = -k*(dT/dx)
<u>Case (1) </u>
dT/dx= (-20-50)/0.35==> -280 K/m
q_x =-50*(-280)*10^3==>14 kW
Case (2)
dT/dx= (-10+30)/0.35==> 80 K/m
q_x =-50*(80)*10^3==>-4 kW
Case (2)
dT/dx= (-10+30)/0.35==> 80 K/m
q_x =-50*(80)*10^3==>-4 kW
Case (3)
q_x =-50*(160)*10^3==>-8 kW
T2=T1+dT/dx*L=70+160*0.25==> 110° C
Case (4)
q_x =-50*(-80)*10^3==>4 kW
T1=T2-dT/dx*L=40+80*0.25==> 60° C
Case (5)
q_x =-50*(200)*10^3==>-10 kW
T1=T2-dT/dx*L=30-200*0.25==> -20° C
note:
all graph are attached
<span>553 ohms
The Capacitive reactance of a capacitor is dependent upon the frequency. The lower the frequency, the higher the reactance, the higher the frequency, the lower the reactance. The equation is
Xc = 1/(2*pi*f*C)
where
Xc = Reactance in ohms
pi = 3.1415926535.....
f = frequency in hertz.
C = capacitance in farads.
I'm assuming that the voltage and resistor mentioned in the question are for later parts that are not mentioned in this question. Reason is that they have no effect on the reactance, but would have an effect if a question about current draw is made in a later part. With that said, let's calculate the reactance.
The 120 rad/s frequency is better known as 60 Hz.
Substitute known values into the formula.
Xc = 1/(2*pi* 60 * 0.00000480)
Xc = 1/0.001809557
Xc = 552.6213302
Rounding to 3 significant figures gives 553 ohms.</span>
Answer:
The boats are 934.65 feet apart
Explanation:
Given:
The angles of depression to the two boats are 42 degrees and 29 degrees
Height of the observation deck i = 1,353 feet
To Find:
How far apart are the boats (y )= ?
Solution:
<em><u>Step 1 : Finding the value of x(Refer the figure attached)</u></em>
We can use the tangent ratio to find the x value
x = 590.47 feet
<em><u>Step 2 : Finding the value of z (Refer the figure attached)</u></em>
z = 1525.12 feet
<em><u>Step 3 : Finding the value of y (Refer the figure attached</u></em>)
y = z -x
y = 1525.12 - 590.47
y = 934.65 feet
Thus the two boats are 934.65 feet apart
Answer:
<em>d. The sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
<em></em>
Explanation:
Let us take the momentum of a photon unit as u
we know that the rate of change of momentum is proportional to the force exerted.
For a absorbing surface, the photon is absorbed, therefore the final momentum is zero. From this we can say that
F = (u - 0)/t = u/t
for a unit time, the force is proportional to the momentum of the wave due to its energy density. Therefore,
F = u
For a reflecting surface, the momentum of the wave strikes the sail and changes direction. Since we know that the speed of light does not change, then the force is proportional to
F = (u - (-u))/t = 2u/t
just as the we did above, it becomes
F = 2u.
From this we can see that the force for a reflective sail is twice of that for an absorbing sail, and we know that the pressure is proportional to the force for a given area. From these, we conclude that <em>the sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
<em></em>
