# Search results

1. ### Extension of rod -- help please

yea h .yeah ,.. im seeing it ,anyway thanks
2. ### Extension of rod -- help please

i didnot mean that way. i value you all. but i was in a hurry,, needed aproach or formula that i miss.exams coming up.
3. ### Extension of rod -- help please

let original lenght be L ... but i have no idea how to find lenght btw consecutive section after load is applied.
4. ### Extension of rod -- help please

only problem im facing is its E value .. at dx E= E1-((E2-E2)/L)*x .im bit confused.
5. ### Extension of rod -- help please

well then the material vary at every point (as u said).. so i need to find extension at given small dx. and integrate from 0 to L . is that right
6. ### Extension of rod -- help please

yes sir .tensile stress =P/A. and strain = dL/L. .by hookes law E=stress/strain giives dL= PL/AE
7. ### Extension of rod -- help please

centimeter by centimeter?. well threre must be some other way, like its going to be triangular profile with one end E1 and other end E2.. is that possible to find equivalent E acting on rod ..
8. ### Extension of rod -- help please

Homework Statement see attachement Homework Equations dl= PL/AE The Attempt at a Solution as you see here my youngs modulus E varies linearly. i doubt that adding up E1 &E2 wld give solution.. any help?
9. ### Airys stress function -- structures

i found other boundary condition too ..beam shear stess (tou)xy=o at y=(-h &=+h)..thanks anyway ..
10. ### Airys stress function -- structures

Homework Statement For (fi)= (b/6) x*y3 +C*xy show that simply supported beam of 2L loaded concentrated load at mid span.,the stress function satisfy loading condition is (fi) .treat concentrated load as shear stress suitably distributed to shoot this function. so that intergtal of limit (h to...
11. ### Harmonic function. vibration

thanks Nas .. i got the solution...sinusoids having frequencies in integer multiple of (f) have net freq (f) when addded together..when i consider by t=1/f ..its pretty clear final net freq occur only after first signal ..so answer is P
12. ### Calculate the Young's modulus

well. i think bulk modulus =direct stress/ vol strain .here pr stress
13. ### Harmonic function. vibration

resultant frequency X=p. Any IDEA how they got it
14. ### Harmonic function. vibration

yes sir but I dont hv known limits in Grapically ..only freq . so by trignometricaL relation i tried it( as u said) ..with sin A+sinB=(1/2)*sin((1/2)(A+b))*Cos((1/2)(A-B)). . i get in the form sin*cos+Sin(C) AND no use of sin A*cosB.. how to proceed here
15. ### Moments Help

yes . take moment about A. consider moment contribution at C ...both X and Y.. u need vertical distance of load that act from base.. that would be 1 . so thats it
16. ### Harmonic function. vibration

Homework Statement three harmonic function of frequency p, 2p ,3p were added together. what is the frequency of resultant periodic function? Homework Equations X=Asin(wt) A-amplitude w-frequency X=X1+X2+X3 The Attempt at a Solution need a hint ..
17. ### Solid hollow shaft

yeah thanks Nas.
18. ### Solid hollow shaft

well .torsion for solid shaft , i have torsion eqn T/J=G*tete/L=shear stess/R but i found finally its torsional stiffness k=T/twist that provide solution. if not i need to do some ground work myself .thanks chester
19. ### Solid hollow shaft

sorry. J represent torsional constant. its the resistance to torsion. im i correct ? ..or how can i use area here to calculate variation in resistance. bit confued :(
20. ### Solid hollow shaft

ok. i get that . so my area of solid shaft = .55*A(hollow ).. but resistance depends on polar moment of inertia right? . j(solid)=pi/32(D)4 .if im not wrong .. then does my shaft resistance decreasce?.
21. ### Solid hollow shaft

Homework Statement internal diameter of a hollow shaft is two third of its external diameter .if it is melted and new solid shaft is made.what would happen to the shaft resistance of torsion. in percentage? Homework Equations as i know T/j=G*angle of twist/length. torsional...
22. ### Calculating landing distance for Flight

yeah.i see it now,its a simple force eqn. thanks all
23. ### Calculating landing distance for Flight

Homework Statement An a/c has an approach speed of45 m/s with descent angle of 7.1 deg. if the a/c load factor is 1.2 and constant deceleration at touch down is .25g (g=9.81).its total landing distance approx over a 15m high obstacle is Homework Equations R=v/g(n-1) Sa=(h-hf)/tan( teta)...
24. ### Replicating a 747-400 Wing Model

yeah.like he said scale down from given aircraft . 2D drawings...idid it many times in cllge year. Using Catia and it came out great.
25. ### Compressor and Turbine Work

use compressor efficiency=ideal/actual entalphy ,for given pr ratio , To1 and effiency ..find only unknown To2 and substitute& find Wc=Cp(To2-To1). so from direct substitution in Wc=Wt . GivenTo3 turbine inlet temp. Find To4 ..Sub in Wt=change in delta To *Cp.
26. ### Rocket propulsion

problem Is we have formula for specific impulse for earth standard..That Isp=Cj/Go Cj-effective jet velocity Go-gravity ..and thats the reason i asked..why its not mars gravity!!! Im not sure of it.
27. ### What are the applications of Damped Oscillation and in future how it can be used?

application in dynamic stabily of aircraft.espically in lateral directional mode eg- dutch roll unstable aircraft..rectify by dampers
28. ### Rocket propulsion

well. I have this question. That my rocket is launched from mar in an return mission to earth. To calculate specific impulse of the rocket. Should i consider mar or earth gravity and if why!? Help me with this