Homework Statement
Homework Equations
Mx=200Nm
My=300Nm
Mz=600Nm
Normal stress caused by bending moment at A = Mc/I = (300*0.02)/((pi*0.02^4)/4)= 47.7MPa. This answer is correct.
Shear stress by Torsional Moment=Tc/J
Polar moment of inertia J=(pi/2)*c^4
So I...
The problem
Why is the normal stress 75/Area and not 125/Area. They are both acting on the same axis so how do I know which one to choose?
And what does (QA) mean?
Homework Statement
I trying to do this hibbeler question which I have modified a bit
However I'm not getting the correct answers which is supposed to be t=17.5 and t=11.3 s
I will take a picture of my attempt when I get a hold of a camera in the meantime if anyone knows how to do it I...
so do i use P=(V^2/R) or P=I^2*R
if i use P=(V^2/R) i get V = sqrootof(25*10)=15.81V
if i use P=I^2*R i get I=sqrootof(10/25)=0.632A V=R*I=15.81V
Then I=V/(RL+RS)= 15.81/(25+5)=0.527A
are my calculations correct?
Two 500μF capacitor are connected in parallel, and then to a 100kW (105W) resistor.
The capacitors are momentarily charged using a 1000V D.C. supply.
Find:
a) The time constant of the circuit.
b) The time “t” taken for the capacitor voltage to decay to 630 volts
c) The current in the...
Explain why “Torque-Speed” matching is important in designing motor-driven
machines. Illustrate your answer with torque-speed plots characteristic of:
i) A fan load
ii) A high static friction load
?!?1?111one
electronics question
Define the term “Speed” as employed in rotating machines, and state its (S.I)
units.
anyone know the answer? is it rad per second?
Homework Statement
A variable resistor (RL) is connected to an unknown circuit. It is found that the
maximum power that can be dissipated in the resistor (RL) is 10W, and that this
occurs when the value of the resistor (RL) is 25ohms.
Derive the Thevenin equivalent circuit for the unknown...
An inductor “L” is connected in series with a Resistor “R”. This circuit is connected to
a sinusoidal voltage “V”, and a current of 1A flows. If the circuit resistor has a value
of 1W, and the magnitude of the reactance of the inductor “L” is 1W at the supply
frequency, state:
(i) The...
1000w should be 1000ohms
Vpk=25/1000=0.25A
Vrms=25/sqroot2=17.68v Irms=17.68/1000=0.0177Arms
Vmean=Vrms*0.9=15.9V Imean=15.9/1000=0.016Amean
Are these result and equations correct? sry don't have a scanner so can't post sketches
Show how two P-N junction diodes can be used in conjunction with a
transformer that has two secondary windings, to form a full-wave rectifier.
(Draw a circuit diagram including connections to the mains transformer).
Explain the operation of your circuit using sketches of waveforms. (3 marks)...
I have three questions and need to calculate the magnitude of the maximum bending moment
1) A 4 m long aluminium alloy beam, simply supported at its ends, carries a central
concentrated load of 2 kN. The T-cross-section of the beam (see Figure A2)
consists of a rectangular flange and web...
Homework Statement
A solid circular steel drive shaft is 4 m long and 60 mm diameter. The modulus of
rigidity of the steel is 85 GPa and its maximum allowable shear strength is 150 MPa.
The shaft is used to transmit a power of 30 kW while rotating at 500 rev/min.
Calculate the following...
Homework Statement
A turbine shaft is to transmit power at 240 rev/min. If the shaft is 1 m external diameter and 25 mm thick and the maximum shear stress is limited to 69 MPa, find the power transmitted.
Homework Equations
The Attempt at a Solution
T=J*stress/r =...