Recent content by sam400

oh, so the diagonal is the longest distance only for a rectangle?

<<Mentor note: Missing template due to originally being posted in other forum.>> So, my professor gave a problem which stated: Given a 15 x 20 rectangle, prove that if 26 points are chosen, at least one pair will be at most five units away. What I said was to split the rectangle into 12 5x5...

Bumping thread. I haven't quite figured it out yet and my TA is busy with finals.

Homework Statement Basically, derive the formula ## m = \frac{ 25 cm}{f_e} \frac{L}{f_o} ## using ray matrices. This just has variable tube length and assumes eye to object distance is 25 cm. Homework Equations Ray matrices: ## \left[ \begin{array}{cc} 1 & d \\ 0 & 1 \end{array} \right] ##...

At the moment, I am a physics major and also putting a lot of emphasis on math. I am in my second year of undergrad at the moment. While my "dream" goal does include going into a PhD for physics, I do realize it's a long and demanding journey, so I have also been looking at actuary related jobs...

so converting it into mass as I did it the second time would be like saying the sample is gaining or losing mass, when in reality the mass just stays constant, it's the particles that's change, which would mean everything has to be converted to number of particles, and the other way would just...

when I used that method, I do get the right answer, but for the alternate method, which is converting alpha/s to g/s, and leaving the thorium to just 1.0 g, I get the wrong answer. The conversion I used for alpha/s to g/s is after the edit on my original post. Since one method works and the...

to convert g/s to alpha/s, I would have to at first take 1 mol/alpha mass in g then multiply by avogadro. This would mean that the conversion I did in the second part was incorrect. However, doing the method described here also gives me a different decay constant value.

dN/dt is in alpha particles per second, and the second is grams per second

Homework Statement Basically, the problem asked for the half life of Thorium-232, given the initial mass and the rate of decay. \begin{equation} \frac{dN}{dt} = 4100 \frac{ \alpha }{s} \end{equation} initial mass = 1.0 gHomework Equations \begin{equation} \frac{dN}{dt} = \lambda N...

The impulse of the dummy will be a negative one, so I feel it might be a sign related problem. If it's something online, it could be significant figure related too, unless the system let's you know about how close the value is from it.

The only thing you need to calculate the force is time. I think you might have to use some kinematic equations for that part, assuming that the dummy underwent constant acceleration.

Would my error just be that the denominator has a 2 and not its square root? I realized I didn't notice that the 2 in the original expression was not under a square root.

Homework Statement The question is as stated: "The ##H_2## molecule has oscillatory excitations. In classical physics the energy can be approximated to \begin{equation} E = \frac{p^2}{2m} + \frac{m \omega^2 x^2}{2} \end{equation}where m is the reduced mass. Quantum mechanics can be applied to...

Oops, I just realized I have been using degrees for my values. Now my error is more sensible. I had 0.3 degrees for my angle uncertainty, but it wasn't converted to radians.