Something seems off about that because if I say A = 1, then
$$A(1-ω^2) - B = 0 $$ $$→$$ $$B=(1-ω^2)$$
And
$$C(1-ω^2) - B = 0$$ $$→$$ $$C = B/(1-ω^2) = (1-ω^2)/(1-ω^2) = 1 $$
But I still have the equation for $$B(2-ω^2) - A - C = B(2-ω^2) - 2 = 0$$ $$→$$ $$B=2/(2-ω^2)$$ which will give me...
Is there another method that you know of? Can I set up a ratio of the amplitudes? My equations after assuming a solution of
X1,2,3 = Asinωt, Bsinωt, and Csinωt are
$$ A(1-ω^2) - B = 0$$
$$
B(2-ω^2) - A - C = 0
$$
$$
C(1-ω^2) - B = 0 $$
1. Homework Statement
A short metal cylinder 145 mm in diameter and 145 mm high at 1045 K
is suddenly exposed (all sides exposed) to a room air temperature at
300 K with h=25 W/m².K. Assume that for the metal k=40W/m.K, den=7800 kg/m3
and Cp=c=600 J/kg.K. Estimate (a) the time required for...
Am I supposed to use the humidity ratio to solve this? I thought the 0.1 kg/s was the mass flow rate of dry air
ω = 0.622 x (Saturated Pressure)/ (Pressure mixture - Saturated Pressure)
The saturation pressure at that temperature is 9.14 kPa using linear interpolation with the saturation tables. Ok, so the rate given was for the mixture which is the same for all components. For some reason, I was thinking each component might have a different mass flow rate.
Then the part I'm...
1. Homework Statement
Only Number 1, not number 2
2. Homework Equations
Dew Point Temperature T = Saturated Temperated at Vapor Pressure
Partial Pressure = (mole fraction) x (Mixture Pressure)
3. The Attempt at a Solution
The dew point temperature is only dependent on the pressure of...
1. Homework Statement
Only Number 1, not number 2
2. Homework Equations
Dew Point Temperature T = Saturated Temperated at Vapor Pressure
Partial Pressure = (mole fraction) x (Mixture Pressure)
3. The Attempt at a Solution
The dew point temperature is only dependent on the pressure of...
1. Homework Statement
A 250V shunt dc motor runs at 1000rpm while taking a current of 25 A. The motor has armature and field resistance as 0.2W and 250W respectively. Calculate
(a) The speed when the load current is 50A.
(b) Armature torque developed at both speeds.
2. Homework...
Zc = Vc/Ic = (240 < 0°)/(15 < 90°) = 2.67 < -90° which means Xc = -2.67i = -i/(ωC)
Edit: Nvm I see that I must've mistyped in my calculator. Zc = 16 < -90°
Now I got C = 199 μF
Hmm ok so I drew the diagram on a graph and got that IC = √[IL2 - I2] which gave me IC = 15 A
Using the voltage source, which is in parallel with the capacitor, I found reactance Xc which gave me C = 1.19mF. Did I make a mistake somewhere?
Ok, so when the problem says that it has a power factor of 1.0, they are talking about after you correct it with the capacitor not before? The wording made it seem as if it is already at unity which made no sense to me. So basically, I have to find the power factor before the capacitor is added...
1. Homework Statement
Not sure if this is the correct place for Electrical Engineering Homework help but here goes
A single-phased motor connected across a 240-V source at 50Hz as shown in the figure has a power factor of 1.0, I = 20A, I1 = 25 A.
Find the capacitance required to give a unity...
Considering just a single gear, you're saying the tangential velocity is different at every point? How is that possible when ω and r are both constant?
These only show me calculations when I know the teeth of the gears. In this problem, I don't know the teeth.
In order to find frequency, I took the tangential velocity of shaft AB and set it equal to shaft CD so that (2πfAB)rB = (2πfCD)rC.
Then the 2π cancels out and I'm left with a relationship between just the gear radius and frequency (fAB)rB = (fCD)rC
. Which would mean that shaft AB frequency of...
1. Homework Statement
2. Homework Equations
tangential velocity v = ωr
angular velocity ω = 2πf
3. The Attempt at a Solution
Not really looking for help to solve the problem. I'm just confused about the speed/angular velocity and frequency
If the frequency of the motor is given as 24...
By "shaded area", they mean the cross-hatched section right? Wouldn't that make the half circle area void as well?
edit: never mind I get what you're saying. Thanks lol. The volume of only the cross hatched section means obtaining that area and coordinate only. Which means I have to subtract...
1. Homework Statement
A steel die, shown in section, has the form of a solid
generated by revolving the shaded area around the
z-axis. Calculate the mass m of the die.
2. Homework Equations
V =θ(rA) where r is the distance from the origin to the centroid of each shape
m = ρV where ρ =...
Well that's great -__-. Also, if I use the conservation of energy, I still get v = √(2aR) but I don't understand how to solve it the same way my book wants me to.
Using W = ΔK where K initial = 0 and so W = K final = 0.5m(vf)^2. If W = ∫ F dr, then what is F?
Am I supposed to use F =...
1. Homework Statement
With what speed would mail pass through the center of earth if falling in a tunnel through the center?
2. Homework Equations
W = -K
K = 0.5mv^2
(vf)^2 = (vi)^2 + 2aΔx
3. The Attempt at a Solution
My main question is why can't I use the last equation...