# Search results

1. ### Java Java 'if' statements

Edit: Never mind guys, figured it out. I needed to use s.equals :) However, could someone explain to me why we can't use == on a technical level? I'm curious to know on a technical level. Hi guys Doing a bit of programming, and I'm not too sure why I'm not getting the expected results. Below...
2. ### Current versus dynamic force on linear actuators

Hi guys, I've had another thought. Assuming same actuator specifications, which of the three scenarios would draw more current from the actuators? Based on my understanding of basic physics, I am inclined to say Scenario B, mainly because the vertical force component of the actuator relative...
3. ### Current versus dynamic force on linear actuators

So the 200lbs actuator should draw less current then, given it has a higher gearing? The actuators will need to lift around 105Kg of vertical load. However, I have both of them opening at an angle of 27.72 given the design constraints. The power of the motor is seems correct, because that is...
4. ### Current versus dynamic force on linear actuators

G'day guys So I currently have a 2x 8" stoke 150lbs dynamic force actuators with a maximum current draw of 5A. The exact one is the FA-PO-150-12-XX in the link below: https://www.firgelliauto.com/products/feedback-rod-actuator The load I have on it causes the actuators to draw almost its'...
5. ### Calculating the Static Frictional Force of Nylon Bushings

Thanks for your responses guys, and apologies; I should've been a bit more clearly on what I'm trying to achieve. This test was to investigate how much variation there is in terms of the force that is needed to overcome the total friction in the hinges that we stock. The method of investigating...
6. ### Calculating the Static Frictional Force of Nylon Bushings

Thanks, that was what I was looking for. I have a few samples of these hinges to do the test, so I hope this will help with the accuracy. Just for final confirmation, would I still use the formula Fs = μsN, in this situation? From what I found out, the above formula is used in a lot of linear...
7. ### Calculating the Static Frictional Force of Nylon Bushings

Hi guys I'm looking to calculate the static frictional force for a hinge Below is a CAD image of the component I am testing. I am thinking of attaching a hook onto the plate as shown below, and continuously add weights at the end of the hook until the hinge begins to move. By multiplying...
8. ### Automotive Calculate the position for a linear acutator

Hey Nidum Thanks for the feedback. Just so I am on the right track... From a practical point of view, it would be best to have the actuator closer to the hinge the as shown below? I am guessing this is more practical for the following reasons: Less intrusive for people to load things at the...
9. ### Automotive Calculate the position for a linear acutator

Thanks Nidum Would the best place to push the lid be at the very end of the lid? As for the angle, would the ideal place be perpendicular to the surface of the lid?
10. ### Calculate the force to stop a train

Homework Statement [/B] Superman must stop a 120-km/hr train in 150 m to keep it from hitting a stalled car on the tracks. If the trains mass is 3.6 x 10^5 kg, how much force must he exert? Vi = 33 m/s (120 km/h) Vf = 0 m/s Displacement (Xf - Xi) = 150 m M = 3.6 x 10^5 kg Homework Equations...
11. ### Automotive Calculate the position for a linear acutator

Hi everyone! So I'm working on project where I have to design a hinge system for a hard lid that is fitted onto the back of a pickup truck. In this system, I will be using 2x linear actuator(s) that will need to lift a total weight of roughly 95kg. At the moment, I've got a selection of 600N...
12. ### Finding real numbers

Homework Statement Please see questions (c) and (e) on the attachement 2.Relevant Equations The Attempt at a Solution So long story short, these two questions were given out as a challenge in one of our Swedish lessons to see if we could remember our high school calculus, which I shamefully...
13. ### Calculating 3-Way Vectors

Thanks Simon and jedishrfu. It turns out it was the wrong calculation in (2) as you guys spotted. Need to triple check my work next time :smile:
14. ### Calculating 3-Way Vectors

Homework Statement Homework Equations The Attempt at a Solution I can't remember what this method of calculation this is as it's been a while since I've done this. [/B] Could someone explain to me what I've done wrong in my calculations? The answer was 13.8N at 80 degrees.
15. ### Equilibrium and principle of moments

Homework Statement Homework Equations Torque = F x D Manticlockwise = Mclockwise The Attempt at a Solution From what I understand, the moment on left hand side of the pivot point needs to be equal to the moment on right hand side, therefore... (Fx.2)+(5x.14) = (7xd) My initial...
16. ### Simple Mechanical Questions

But how would that formula work though? I wouldn't be able to solve for c, since I'm asked to find the diameter. If I substitute that in, then I'd have \frac{M\frac{d}{2}}{\frac{∏d}{64}}=σ where c = \frac{d}{2}
17. ### Simple Mechanical Questions

Homework Statement A) A circular rod is subjected to a bending moment of 315Nm. What is the minimum diameter of the rod required so that the maximum stress does not exceed 200N/mm2? B) If the Modulus of Elasticity for the material from which the rod is made of is 100kN/mm2, what radius...
18. ### Building a NOT gate

Righto, thanks for confirming that
19. ### Building a NOT gate

Is it possible to building one from using AND and OR gates, cause I've been trying and now I'm wondering if it's even possible
20. ### Fourier Transform using Modulation

Homework Statement Find the Fourier Transforms f1(t) = \frac{2}{3-it} f2(t) = \frac{2}{3-it}cos(t) Homework Equations F{H(t)et} = \frac{-1}{-1-it} F{f(t)cos(\omegat)} = \frac{1}{2}[F(\omega+\omega0+F(\omega-\omega0)] The Attempt at a Solution For the first question, my...
21. ### Engineering Using Thevenins therom to solve a simple circuits

Got it, thanks a lot!!
22. ### Engineering Using Thevenins therom to solve a simple circuits

Using Thevenins therom to solve a "simple" circuits Homework Statement The problems I am stuck on is problem two, figure 1 and figure 2. It's attached to this post. Homework Equations The Attempt at a Solution My initial attempt at solving for Rthev for figure 1 was that...
23. ### Identifying Gate Logic

Oh right, sorry, don't know what I was thinking when I was typing haha! Thanks a lot!!
24. ### Identifying Gate Logic

Hi there I'm currently doing a digital fundamentals paper and I was wondering if anyone could identify a logic symbol on the spec sheet attached, and what's it used for. It's on page 4, and the logic symbol is a diamond that is surrounded by 4 traingles. Theres eight of them and it's near...
25. ### Finding the lifespan of a telescope mirror (probability question)

Oh I see what you've done. Independant Events are probabilities that either one occurs is not affected by the occurance of the other P(A \cup B) =P(A)P(B) So for question one; [e^-(5/10)^5]*[e^(5/10)^5]*[e^(5/10)^5] = 0.9105 :smile: question two; [1-P(All less than 7 years)] = [1...
26. ### Finding the lifespan of a telescope mirror (probability question)

Heres my logic In question a), it asks for the probability of "at least for 5 years". To me, it says find the probability between 5 \leq X \leq \infty. Since I can't substitute infinity into t, so what I did was put in 4 instead. This way I can was hoping to find the probability of the...
27. ### Finding the lifespan of a telescope mirror (probability question)

Homework Statement A telescope contains 3 large mirrors. The time (in years) until a single mirror fails has been investigated and we know that the probability that a mirror is still fully functional after t years is e^(-(t/10)^5 ) a) All mirrors must be working to take the most detailed...
28. ### Quality Control Charts

Hi all I'm having a bit of trouble trying to calculate the Upper and Lower Control Limit on R chart. The file "QualityIndex1180" contains the information from which I'm doing my calculations. Ob1, Ob2, and Ob3 are basically 3 samples that have been taken the first of 15 batches on some...
29. ### Conic Equation using a Quadratic Form

Got it! Thanks!
30. ### Conic Equation using a Quadratic Form

Homework Statement x12+x1x2+2x22=8 a) Write the equation using a quadratic form i.e. \underline{x}TA\underline{X}=8 b)Find the Matrix Q such that the transformation \underline{X}=Q\underline{Y} diagonalises A and reduces the quadratic form to standard form in terms of coordinates...