1. ### I Meaning of each member being a unit vector

Summary: Meaning of each member being a unit vector, and how the products of each tensor can be averaged. Hello! I am struggling with understanding the meaning of "each member is a unit vector": I can see that N would represent the number of samples, and the pointy bracket represents an...
2. ### Where can I find historic daily average temperatures?

I am a middle school teacher who is very concerned about global warming. My students’ memories don’t go back very far and they think it is perfectly normal to see mild weather and little to no snow throughout the winter months in New York City. I would like to compare current temperatures each...
3. ### Mean Frequency and Frequency Spread of a Laser Pulse

Homework Statement Laser probes are being used to examine the states of atoms and molecules at high temporal resolution. A laser operating at a wavelength of 400 nm produces a 1 femtosecond pulse. Compute the mean frequency and frequency spread, ∆ν, of this laser pulse. Homework Equations c =...
4. ### I Standard deviation of data after data treatment

I was given the averages (AVG) and the corresponding standard deviation (SD) of sets of data. I have no copy of the raw data for each data point that were used to calculate the AVG and SD. I performed further data treatment on the data. I want to ask what is the relationship between the...
5. ### How many significant figures in the average area?

Homework Statement I've been given a list of lengths of the side of a small metal sheet in the shape of a square. The length of the side of this square sheet varies with temperature. I have to calculate areas for each length and then calculate the average area. What should be the uncertainity...
6. ### I can't quite get this question... (|Uav|)

Homework Statement John is entering Steward, and drives West, with a Uav of 88 km/h. He arrives at Aurora, and realises he took a wrong turn. He turns around and drives East, towards York, with a Uav' of 79 km/h. Steward-Aurora is 76 km & and Aurora-York is 34 km. For the whole trip (S -> A ->...
7. ### A question about Rectilinear motion

Homework Statement Q: If a particle moving along a straight line under uniform acceleration covers successive equal distances ( S each) in time intervals t1, t2 and t3 respectively, then the expression for average speed of particle in covering the given distance of 3S is: Options: A) (S/t1)...
8. ### Question on Deriving Physics Equations

So I am teaching myself physics in "Physics 1 For Dummies" and I have come across a chapter dealing with deriving equations, this one being the distance through using the average velocity. I have never derived equations before, so be easy on me! So basically it starts off with s=vt (distance...
9. ### Average and rms values of a given signal

Homework Statement I am in an Intro to EE class and we were given a homework assignment including the following question: Find the average and rms values of the signal: x(t)=3cos(7ωt)+4 I have formulas for average power and rms but they include V & I, however the signal was given as x(t). I...
10. ### Adding increasing fractions without averaging numerators

I'm interested in the following inequality (which may or may not be true) Theorem 1: ##( \sum_{i=1}^n \frac{a_i} {n}\ )( \sum_{i=1}^n \frac{1} {b_i}\ ) > \sum_{i=1}^n \frac{a_i} {b_i}\ ## Where ##n ≥ 2, a_1 < a_2 < ... < a_n## and ##b_1 < b_2 < ... < b_n##. My attempt at a proof: 1) When n =...
11. ### What is the average of fall distances

[no template, as this post was moved from here from the Quantum Mechanics forum] In griffiths 2nd quantum mechnics, problem : Suppose I drop a rock off a cliff of height h. As if falls, I snap a million photographs, at random intervals. On each picture I measure the distance the rock has...
12. ### Momentum/Impulse- Calculating Average Force of Raindrops

Homework Statement The problem says: "A record rainstorm produced 304.8 mm (approximately 1 ft) of rain in 42 min. Estimate the average force that the rain exerted on the roof of a house that measures 10 m * 16 m. Indicate any assumptions you made. (Note: density of water is 1000 kg/m3"...
13. ### General math to find average

the question statement is 2. In a course, a student's final exam is weighted twice as heavily as his midterm exam. If a student receives a score of 84 on his final exam , 90 on his midterm, what is the average for his courses? now i am pretty confused should I have to know the total marks for...
14. ### Average velocity, displacement vector.

Homework Statement Suppose that a car moves up north 100 km for 2 h and then turns towards east and travels in this direction 60 km for 1 h. a. Draw in the following diagram the displacement vector of the car? b. Determine the average velocity and the speed of the car. c. Answer the question...
15. ### Uncertainty of an average

Homework Statement I am analysing intensities of some pictures. There are specific regions of higher intensities and so far i have managed to locate those regions automatically in Mathematica and the program returns the average intensity and standard deviation on this regions ("circles"), so I...