1. ### Why are two pieces of wood stronger when bound together?

The answer learned in class is that the two 2*4s are able to distribute the load over both of them, but I don't think this is an actual answer because that's balanced by the fact that each block is half the area. Does anyone know of the reason for this observation? Thanks!
2. ### Physics lab report calculating resultant forces -- help please

i have attached my attempt above i have sent it to my teacher and he said i should fix the mistakes and resend it
3. ### Other Not Sure What To Specialize In, Or Where To Go For My Program Of Study

Hello, Currently I am an undergrad about 1 year or 3/2 year(s) away from graduating with a double major in computer science (which I am a lot stronger in) and physics. I have always been interested in advanced propulsion. I would really like to do research on the...
4. ### Finding the Average Acceleration

Hello, so I am working on a projectile motion lab but I'm not sure what to do right now. Essentially, the lab consisted of my classmates and I using an air table to show that the vertical and horizontal components of projectile motion are independent. During one of our trials, we placed a puck...
5. ### Programs Seeking advice on how to search for a Graduate School in Molecular Biology

Will finish B.S. in molecular biology in May. Have found asking vague questions about where to go/apply to next are pretty unhelpful. I believe that going through indexes of interesting research is the closest I can get to finding a place to advance myself and be happy in. here is an example...
6. ### Centripetal Lab- finding the mass from the slope

Homework Statement The lab: Centripetal Force Lab a Rubber stopper is moving in a horizontal circle at a constant radius and it is attached to a string where at the bottom, there is a mass where the mass is 100g, 150g, 200g, 250, and 300g (can see image attached) from the lab, I collected...
7. ### Identifying Unknown Bacteria

Homework Statement I have done tests on this unknown bacteria and this were the results: Cocci shape Gram (-) negative Catalase (+) positive (only one bubble though) Oxidase( - )negative Has endospores (used Schaeffer-Fulton method) Antibiogram: Resistant to Streptomycin...
8. ### Ladder Leaning against wall -- find the coefficient of friction

Homework Statement Ladder leans against wall at angle θ. It is L meters long and mass m. Find the coefficient of friction with the floor. Assume no friction at the top.[/B] Homework Equations ΣFx = 0 ΣFy = 0 Στ = 0 ƒ = μFn (Fn being the normal force with the ground) The Attempt at a...
9. ### Sources of Error in a Speed of Sound Experiment

Homework Statement Determine sources of error which could have affected the results. Some background information: The lab consisted of playing a tone generated by a tone generator above a standing open-closed tube which had water in it. The first harmonic was measured through a computer system...
10. ### How to do electrical conductivity tests?

<< Thread moved from a technical forum, so no HH Template is shown >> Our teacher gave us a lab, and we have to write a procedure on how to test the electrical conductivity of multiple substances. However, on the materials, all that was written was "electrical conductivity tester", which I'm...
11. ### Mohr's Circle does y-axis = max strain or max strain/2?

This isn't a problem assignment per-say, but for a lab calculation. In my mechanics of material's class, we learned that the radius of Mohr's circle is the maximum strain, but now in my application lab-based class, the video is saying the radius is equal to the maximum strain divided by 2. So...
12. ### How can I stop condensation (not fog) build-up on my goggles?

I have uvex stealth anti-fog chemistry goggles, and in lab the lenses build up with dew. It becomes so bad that I can't see and I have to regularly exit the lab every 15 minutes to wipe them off. I sweat when in the lab, so I'm not sure if that's why . There's no fog, just pure dew drop...
13. ### Variables in a lab (controlled, independant and dependant)

Hi! So it's new for me to do physics lab that way and my teacher is asking us to define the independant, dependant and controlled variables of every lab we're doing. I'm not quite sure what they refer to... For example, in a moment of inertia lab (see picture), I am asked this question. The...
14. ### Conical Pendulum Lab

So I'm doing a lab in class, and when I graphed the Period vs Length of the string, I got it in the form $T=A\sqrt{L}$, but I don't really know what the value $A$ represents nor what its unit is... Can someone help me?
15. ### Calculating B:I for Helmholtz coils

Homework Statement I've completed an experiment where the dependence of magnetic field strength ##B## on current ##I## is measured at the midpoint along the axis between two Helmholtz coils (separation distance = coil radius ##r##). I got the expected linear relationship from the data but am...
16. R

### Magnesium Oxide lab

So in my experiment we combusted Magnesium ribbon to form Magnesium oxide. These were the reactions: Mg(s) + N2(g) + O2(g) → MgO(s) + Mg3N2(s) MgO(s) + Mg3N2(s) + H2O(l) → MgO(s) + Mg(OH)2(s) + NH3(g) MgO(s) + Mg(OH)2(s) → MgxOy(s) + H2O(g)...
17. E

### B Help with Physics lab idea (creative)

Hiya! In school we have tha task to create our own phy lab. I am going to investigate the width of a hair using wave diffraction (a laser maybe?). Does anyone have any creative ideas on how to develop the lab to make it more uniqe and interesting. E.g measuring from different distances. Or...
18. ### Schools What is best for me, applied physics or pure physics?

I'm currently finishing up my second year in college and I'm expected to graduate on time (in two years) and I'm majoring in pure physics. I don't really fully understand the difference between applied physics and pure physics because anytime I look into it online there's 10 different answers...
19. ### I Setting up a circuit to drive a Laser Diode

Hello fellow physics friends (alliteration: always a strong opener). I am writing today because I find myself struggling to complete something which ostensibly doesn't seem that difficult to the average physics undergrad working in a lab. However, electronics and circuits are definitely a...
20. ### Kinematics physics lab help sources of error

1. The problem statement of my lab I have this physics lab where I have to find the maximum velocity and maximum acceleration of a high school student sprinting/running using carbon tape and a spark timer. Which I already did. Now I'm having trouble developing my sources of error section. I hope...
21. ### Separation of Mixture Lab

Homework Statement In this lab we are going to be given a mixture containing sodium chloride [NaCl], silicon dioxide [SiO2], Iron filings [Fe], and calcium carbonate [CaCO3] The goal of the lab is to use separation and measurement techniques to determine the percent by mass of each specie in...
22. ### Help with diffraction flashlight lab activity...

I'm updating some poorly written lab activities for an online physics class that I have been given, and I am going through the experiments and doing them myself to better write them. I came across this one, and I have no idea what the results are supposed to be. It comes after the chapter on...
23. ### What if a chemical reagent reports purity as a range?

I have a chemical reagent that says: Assay ... 93.0 ~ 103.0% Which value should I use in theoretical computations? Should I take the average or the lowest value? Thanks!
24. ### Lab: Plot graph of resistance, R (in Ohms) versus 1/d^2

Homework Statement We were given five samples of nichrome wire, each with a different diameter but the same length. A micrometer was used to measure the diameters. We then measured and recorded the electrical resistance, R in Ohms of each nichrome sample with a DMM. I will try to summarize all...
25. ### I Random Error in Lab report

I'm currently in first year engineering and I seem to be struggling with Physics, which is not unlikely uncommon. A simple problem I've come across is not doing correct error analysis when writing up lab reports. In my current lab, which is justifying the relationship of angular frequency...
26. ### Newton's second law lab

Homework Statement Hi, Im doing this lab this week, but before I do it I have a few questions. ( it has to be completed in class so I wanna be prepared). First, these are the three pages of the lab questions: Page1-http://i1076.photobucket.com/albums/w457/Hbjoi_Hggo/image.jpg1_zpss9wvh4bs.jpg...
27. ### When is resistance large enough to be measurable?

Homework Statement We conducted experiments using copper wires to observe the effect length has on resistance. We measured lengths from 5 - 30 cm and used a multimeter to measure the voltage while supplying a constant current from a power supply package. The multimeter measures in mV. Plotting...
28. ### What should I title my lab?

Homework Statement We recently conducted a physics lab in class where we designed an experiment to "prove" the kinematic equations. We used photogates, ramp and a car. Homework Equations We have to show v = u+at and the other kinematic equations are true with our collected data. The Attempt...
29. ### Physics Lab -- Don't Understand Procedure...

I have a physics lab and the main question is: 'How does the radius of the loops of a solenoid affect the magnetic field produced by the coil?' For my hypothesis, I wrote: "The larger the radius of a solenoid is,the weaker the magnetic field will be." I searched online and found out I was...
30. B

### LeBron James' Verizon science experiment

In the current Verizon ad featuring LeBron James in a physics lab, there is an instrument displayed prominently in front of each student. What is it?