Recent content by Chris L

Ah, that makes sense. I was considering the work done from the frame of the walking person (which would be zero), not the observer. The net force on the rock still points along the string but F•d isn't zero because of the non-circular path the rock takes in the observer's frame.Followup...

Homework Statement Not a homework or coursework question, but given the simplicity of the problem I feel that this is an appropriate subforum. Consider a person spinning a rock on a string above their head at a constant angular velocity, walking away from the observer at a constant linear...

Oh wow, I can't read it seems, that would explain it. Thanks for your help!

From the math courses I've taken, I've always been told that indeterminate forms mean that the function isn't defined at that point, rather than defining the value at that point to be equal to the limit. I can see the advantages of that convention, but that doesn't account for 36, where for...

As a preface, this question is taken from Vector Calculus 4th Edition by Susan Jane Colley, section 2.3 exercises. Homework Statement "Explain why each of the functions given in Exercises 34-36 is differentiable at every point in its domain." 34. xy - 7x^8y^2 cosx 35. \frac{x + y +...

Thank you for all of your help! I'm new to PF, is there a way I can give you a thumbs up or points or something?

Oh wow, I made another calculator mistake, -log10(0.0336) isn't 3.39, it's 1.474. Should that be the correct answer then?

I'm more concerned with the correct process than the right answer, my new answer being farther from the correct one doesn't bother me because I've fixed an error. I'm not quite sure what you mean by the second statement; in the solution there exists Na+, H+, F-, and I-. From what I...

Fixed the original post, I really have to get new batteries for my TI-89...I make too many mistakes with the windows calculator. Thanks for the response! After fixing the numbers, the pH is now 3.39, although the highest pH given in the answers was 2.5 (it was multiple choice). The professor...

Homework Statement Determine the pH at the equivalence point after 20.00mL of a 3.75 M NaF(aq) solution is titrated with 3.25 M HI(aq) Homework Equations ##k_a = \frac{[A^-][H^+]}{[HA]}## The Attempt at a Solution The first thing I noted was that NaF ##\rightarrow## Na+(aq) +...

So for that particular problem, there doesn't happen to be a solution since 2 = 5k and 3 = 6k, and obviously there isn't a value for k that satisfies both of those. Thanks for your response

Two quick questions: 1. Are two vectors considered collinear if the angle between them is 180°? (My guess would be yes, but it can't hurt to double check) 2. Let's say you're given a problem like this: "given A = (1, 2, 3) and B = (x, 5, 6), find the value of x such that A and B are...

I guess I just have to keep in mind that math doesn't govern physics; it's sometimes hard to remember that though when the math you're doing in physics is more advanced than the math you're doing in math. A sonic boom occurring right at Mach 1 makes a lot more sense...I double checked and...

On our grade 11 physics exam, there was a question asking for the minimum velocity of a jet in order for it to produce a sonic boom (the temperature of the air was given, so the speed of sound in the situation was known). According to our textbook, a sonic boom is produced only after the jet's...