# Search results

1. ### Ultimate Tensile strength of ductile materials

In case of ductile materials we know that there is a substantial difference between the ultimate tensile strength and yield strength. As long as the specimen stress is below the yield strength we need not worry about engineering stress and true stress, as they as essentially same. But when...
2. ### Doubt on Fatigue Strength S-N diagrams

A standard way of plotting an S-N (fatigue strength vs no of cycles) graph is to start off by taking a value of Sm (for N=1000) cycles and joining it to the point depicting Se(Endurance Limit). Now we commonly take Sm= 0.9Sut for steels. Now I was wandering, before you actually get to use the...
3. ### Doubt Regarding Shearing Stresses In a Beam

Thank you AlephZero for the reply, but could you please elaborate which integral you are talking about. The derivation for shear stress the way I know it is that you take forces due to moments (axial) for a small element in either direction. If the element length is dx the change in moment is dM...
4. ### Doubt Regarding Shearing Stresses In a Beam

Thank you pukb for your reply. SO basically its right when i say that the shear stresses in the xy(towards the downward portion) is actually zero. Which means maybe the material out there does not tend to get sheared? Maybe true but hard to digest. I am having problems as to how to visualize...
5. ### Doubt Regarding Shearing Stresses In a Beam

Lets say we have a beam which is simply supported at the two extreme ends(support conditions dont matter in my question). A concentrated transverse load is applied at the halfway point. Now lets say we take a section at x= L/3 where is L the length of the beam. Now we know that transverse shear...
6. ### Roll cage design

I would like to thank you both for your replies... But before I go ahead I would like to correct myself... Max speed is 60 mph and not 6. So coming to what I did. I think I should go ahead by building a Base first. We are planning on going for something with a rectangular outline with a front U...
7. ### Roll cage design

As of now my only concrete source were SAE Baja Team reports. But My situation is different. Out there they had fixed the thickness and outer diameter of the roll cage tubes and the basic structure of the roll cage was fixed - All part of the rules. In my case i dont know how to start. All I...
8. ### Roll cage design

I am a bachelors mechanical engineering student with a decent factual knowledge about cars and how they work. But i am a novice with no experience when it comes to design. Now I (along with 3 other guys) have been assigned the task of designing the roll cage of an electric car. I did not get any...
9. ### Wire tensions homework

Ok.....i got it using the fact that notes is corresponding to the fundamental frequency....Thanks...
10. ### Oscillation of cylinder attached to two springs

Oscillation of cylinder attached to two springs.... Homework Statement A solid uniform cylinder of mass m performs small oscillations due to the action of two springs attached at its topmost point. Spring have spring constant k. Find time period of these oscillations in the absence of...
11. ### Wire tensions homework

And what is the significance of saying that they are from the same source?
12. ### Wire tensions homework

Are you talking about the concept of standing waves where the length is an integral multiple of (wavelength/2). In this case they are not talking about any particular frequency (fundamental or 2nd overtone 3rd overtone whatever....).....So how do i get the wavelength?
13. ### Stationary waves equations

I am still not clear..how are they travelling in the same direction? if the velocities have opposite sign....
14. ### Change in density of water

my answer is 2.12618 and answer in the book is 2....I guess they are expecting this answer .......But ya it should be close as we are dealing with values of pressure musch lesser than Bulk modulus of water.....But this is'nt a correct method is'nt it? Neway.....thanks a lot for your help....
15. ### Change in density of water

Ok...thanks i will try it.... I am sorry i didnt notice your reply for a long time.....
16. ### Oscillations of a complicated spring block system

Homework Statement A 4kg block M in horizontal plane is attached to a sprig S1 fixed to a light rod OA of length 4m as shown in diagram(refer to attachement). The other end O of the rod is hinged to rotate in the plane about the vertical axis passing through it. A spring S2 is fixed to the mid...
17. ### Current electricity and circuits

This time....the current through current is independent of K2.....right..... In the book the answer for internal resistance is as you say 0 but R1 is 50.... But R1 cant be non zero because in such a case the current in ammeter is not independent of k2.....Isnt it? So R1 = 0 and Ri being 0 is...
18. ### Electrostatics - Finding amount of heat in a circuit

Please can anyone point out if there is any error?
19. ### ELectric field inside a cavity

Hmmm......you are going by repulsions and i was trying it explain it by thinking that potential has to be same throughout so if there is accumulation of extra charge at some point it violates this and hence doesnt make sense.....That is fine it we are talking about a solid conducting sphere with...
20. ### Current electricity and circuits

Ya.... i agree with you.....So basically it seems there is something wrong with the question isnt it? I guess better off leaving it.....Just wanted to confirm that my concepts are fine..... Thank you gneill....
21. ### Intensity and Superposition of waves

Hi jambaugh...thanks for your reply .... I got the identity but how does it apply here? im afraid i still didnt get much of a clue about how this equation comes.....
22. ### ELectric field inside a cavity

Hey Berko.....thanks a lot.....your explanations almost perfectly satisfies my queries.....But one small thing.....You say that the charge distribution on the outer surface is uniform and it has no connection with whatver is inside and i have read this thing in books but no where have they given...
23. ### Intensity and Superposition of waves

Intensity and Superposition of waves.... Homework Statement Incident wave y=Asin(ax + bt + pi/2) is reflected by an obstacle at x=0 which reudces intensity of reflected wave by 36%. Due to superposition a resulting wave consist of standing wave and travelling wave given by y= -1.6 sinax.sinbt...
24. ### ELectric field inside a cavity

I am waiting for some more replies...please....
25. ### Current electricity and circuits

Waiting for a reply soon.....thank you....
26. ### Standing waves

Any help here?
27. ### Stationary waves equations

But how can one write it as sin(w't+kx)......w has to remain same and has to be positive... And ya....how does it explain why 2 and 3 can not form a standing wave?
28. ### Electric field

Field in side the conductor is zero ....But i am not getting what you meant by charge density/distribution on a line between O and S.....
29. ### Electric field

Hi...i am really sorry all af them are perfect spheres....actually i drew this using paint so this is what i managed ....
30. ### Wire tensions homework

Ok.....so notes are simply their frequencies? ok if so then i am assuming both wires to be of the same material....I have velocity given by √(T/density*A) ...here T = tension , A=cross sectional area.....Now i have the ratio of their velocities.....But if i want to use f=v/wavelegth i dont...