Average Definition and 1000 Threads

Homework Statement A ball of mass m= .25kg is moving with an initial velocity of \vec{v}=(8.0\hat{x}+8.0\hat{y})(m/s). It rebounds from a wall and has a final velocity (after impact) of \vec{v}= (-5.0\hat{x}+6.0\hat{y})(m/s) a.) Determine the impulse exerted on the ball by the wall...

This thread is geared towards biology professionals who have only attained a Bachelors degree in the biology/science related field and who have had a minimum work experience of 5+ years. Long story short, I'm an average sophomore pursing a BS in Biology, age 28 and have already been thinking...

Homework Statement Given two positive numbers calculate their weighted average(Note: This is not actually a homework question, but silly me have doubts, so I put it in this category) Homework Equations Two given positive numbers a,b. No separate weights are available to weigh each...

Hi guys, I am doing some research into McDonalds and it's international businesses. It's a small study for people who are interested in good company structures. I came across a section in their annual report where they give some weighted average figures but I don't know how they arrived at...

Hello Everyone, Happy Thanksgiving. I have physics issues. I went around the entire boundless universe in the last two days, and found out the Schrodinger forgot to develop the math for the momentum expectation value for a 2-D particle in a box. It's nowhere to be found. I am a chemistry major...

Homework Statement Homework Equations =̿+2̅, =̿−2 =4̅, =3̅ The Attempt at a Solution From what I gather, we can use the sample range, which is the max minus the min, or the average moving range which is the sum of the preceding value minus the current value divided by the...

Very simple question -- Average speed for a journey Homework Statement Tyler travels a distance (in a straight line) of 18km in 30minutes. iii)Tyler Returns home following the same route in the same amount of time. Write down her average speed and velocity for this journey, explaining why...

Hi Physics Forum. I have just finished one of my exams, in my undergraduate physics program. I haven't yet received the result, but my gut feeling tells me that it hasn't gone as usual. This makes me wonder, what the mean grade for the bachelor degree in Physics is (ore what a good average...

Show that the average force of gravity between Earth (mass = 6.0 X 10^24kg) and the moon (mass = 7.4X10^22 kg) is 2.1X10^20 N. The average earth-moon distance is 3.8 X 10^8 m

I have stumbled upon an approximation to the average of integer square roots. \sum^{n}_{k=1}{\sqrt{k}/n} \approx \sqrt{median(1,2,...,n)} Sorry I am not very good at LaTeX, but I hope this comes across okay. Could anyone explain why this might be happening? In fact, I just discovered that...

Homework Statement A wire loop of resistance R and area A has its normal along the direction of a uniform magnetic field, B. The loop is then flipped over in a time Δt so that its normal is opposite to the field. a) Calculate the average induced EMF. b) Find the average induced current. c) If...

Average Separation of Muon and Proton Homework Statement A muon is a particle with a mass of 206.7 me where me is the electron mass, and with the same charge as an electron. It can be captured in "orbit" by a proton to form a muonic hydrogen atom. a. Find the average separation <r> of...

I know that there is an equation for an accelerating object that is already a notable fraction of the speed of light (force = gamma^3 * mass * acceleration), but gamma is changing while the object accelerates so what i want to know is how to calculate the average acceleration of an object when...

Homework Statement A closed volume is bounded by conducting surfaces that are the n sides of a regular polyhedron (n = 4,6,8,...). The n surfaces are at different potentials Vi, i = 1,2,3,...,n. Prove that the potential at the center of the polyhedron is the average of the potential on the n...

A 1200 kg car start from rest and coast down a uniform grade, at the bottom of which ti has a speed of 20 m/s. If the car has traveled 800 m along the grade and has descended 35 m, what is the average retarding force(friction) encountered by the car? How would I solve this problem? I know Fx =...

Homework Statement A football player whose mass is 85 kg throws a football with a mass of 0.8 kg against a post. The football hits the post traveling horizontally with a speed of 25 m/s, and then it bounces back with about the same speed. The football is in contact with the post for 0.05 s...

I want to become a researcher in physics (or some other scientific field) but unfortunately my undergraduate grades in physics have so far not been too spectacular i.e. a low 2:1 in the UK. When looking at career profiles of various people in research areas I have considered, everyone seems to...

Homework Statement Two closed containers A and B contain equal number of moles of ideal gases GD (diatomic)and GM (Monoatomic) ,respectively. Q .1 a) If the temperature of gases are same,which of them has more average translational kinetic energy ? b) Which of them has more...

Can someone explain this? http://puu.sh/4LNE6.png What is the relevance of t1 < t2 < t3

I'm a physics major in my second year of undergrad. I am taking physics 1 and am also trying to study the MIT opencourseware for physics 1 in conjunction with my course. I have to say, the MIT course seems FAR more comprehensive and requires a lot more study time to get it all down. Maybe it...

Physics average force need help! Homework Statement A coach is hitting pop flies to the outfielders. If the baseball (mass = 145 g) stays in contact with the bat for 0.09 s and leaves the bat with a speed of 84 m/s, what is the average force acting on the ball? Homework Equations...

Homework Statement 620 seconds after starting its take-off, a 260000 kg jet reaches its cruising altitude of 9200 meters and flies with a speed of 235 m/s. Neglecting friction, what has been the average power output of the engines? Homework Equations ΔKE = Work Power = Work/time...

This isn't actually a homework problem, I'm just wondering what I'm doing wrong: Homework Statement Say we've got a stationary brick wall, and a blob of jello with mass m is launched at the wall with speed v. The blob has length d along the direction of motion. The blob splatters...

Homework Statement A traveling wave pulse is shown in figure 1 below, traveling at v=6 m/s across a string. In figure 2, a short segment of the string is shown zoomed in. The angle of this string goes from θ1 = 17o to zero within a small horizontal distance Δx = 3 mm. Homework...

Homework Statement A very hard rubber ball (m = 0.2 kg) is falling vertically at 3 m/s just before it bounces on the floor. The ball rebounds back at essentially the same speed. If the collision with the floor lasts 0.05 s, what is the average force exerted by the floor on the ball...

Homework Statement This is a real world application I'm attempting to solve, but I'm unsure how to get started. I have three contiguous segments of equal length and I know the average velocity for the first two segments. Assuming constant (but unknown) acceleration, how can I calculate the...

Homework Statement Using the trig product identity, cosαcosβ=\frac{1}{2}[cos(α+β)+cos(α-β)], show that the time-average power at the detector can be written as Pavg = 1+cos(δ) That = is supposed to be a proportional symbol. Homework Equations Other than the ones given in the problem...

the height in ft of a baseball, t seconds after being thrown straight upward, is given by h(t)=36t - 16t^2 1) find the average speed of the ball for a) 0≤ t ≤1 b) .5≤ t ≤ 1 c) .9 ≤ t ≤1 the answer to a) is 20 ft/sec, which is what you get if you plug 1 into the equation. the answer to b)...

Homework Statement I have a question can the average value for an integral be negative. I don't see why not just checking. You know this evalutation f_ave = (1/b-a) ∫ f(x) dx Homework Equations thx The Attempt at a Solution

Homework Statement What is the magnitude of the average force required to stop an 1500kg car in 8.0s if the car is traveling at 75km/h ? Homework Equations The Attempt at a Solution

Here is the question: I have posted a link there to this topic so the OP can see my work.

The Equipartition Theorem states that each quadratic degree of freedom contributes 1/2 kT of energy. This can be derived for the translational degrees by integrating the average kinetic energy multiplied by the Maxwell velocity distribution: \int_{-\infty }^{\infty } \frac{m v^2}{2}...

Homework Statement A driver maintains a steady speed of 30.0 m/s for 55 min and then slows to 10 m/s for the next 5 mins. Determine the the total distance traveled and the average speed for the trip. Homework Equations a = v−v0/t The Attempt at a Solution a = 30 - 10 / 60...

Homework Statement Show how you would find the average distance between gas molecules at a specific volume, pressure and temp? Given; Pressure=P (torr) Temp=T (Kelvin) n=number of mol N=number of molecules Volume=V (cm)^3 Homework Equations pv=nRT N=n*(NA)...

My physics problem ask me to find the average acceleration on a velocity time graph. On the graph, velocity is at -6 constantly from 0 - 5 s. I know that an question to use would be average accerlation = delta v/ delta t The problem is I did that and I still got it incorrect on...

Homework Statement The problem is located here http://www.chegg.com/homework-help/determine-average-rms-value-waveform-depicted-fig-1136-chapter-11-problem-26e-solution-9780073529578-exc Homework Equations Rms=sqrt(1/T∫ from 0 to T of i(t)^2 DT ) Average= couldn't find an equation in...

"5 students time a bowling ball traveling from point A to point B. They record the following times": 2.45s 2.49s 2.58s 2.55s 2.51s "7 students measure the length of a car. They record the following lengths": 4.5 m , 4.7 m , 4.4 m , 4.6 m , 4.8 m , 4.5 m , 4.6 m Homework Equations...

hi, how can I calculate average of cos2x ? I want to take average over a sphere I tried to do like this: <cos2X>= 1/2π ∫cos2xdx and I get 1/2 but in my books, wrote that average of cos2x , taken over a sphere, is 1/3

Hi all, It's been a while since I have asked a question here, but statistics has never been my forte. I have the feeling that although I know the definitions I do not completely grasp the concept of confidence intervals. Unfortunately I do need to come up with something sensible here. The...

Hello MHB, I have no good ideas on how to go about solving the following: Let $f:[a,b]\to\mathbb R$ and $g:[a,b]\to\mathbb R$ be real values functions both of which are differentiable in $(a,b)$. Show that there is an $x\in(a,b)$ such that...

I am slightly confused by the definition of average power if the power function $p(t)$ is sinusoidal. Why is it that only one period is considered? I mean I know that it simplifies calculations but if we assume that the period of $p(t)$ is $T$ and I compute the average power over...

I am a second year M.Sc. Physics student in an Indian university, I am highly motivated to pursue a carrier in theoretical high energy physics. I am willing to get a Ph.D. from a European university(as they have 3 year Ph.D. programs, unlike a 5 year program here in India and US). But the...

Start with an infinite 2d grid of cells, with each cell randomly colored black or white (50% chance). Now take the graph G whose nodes are the cells, and with an edge (A, B) if A and B are adjacent in the grid, and the same color. What is the average size of a connected component of G? Is it...

Hello, I'm studying The Theory of Polymer Dynamics by Doi and Edwards and on page 98 there is a tensor, defined as a composition of two identical unit vectors pointing from the monomer n to the monomer m: \hat{\textbf{r}}_{nm}\hat{\textbf{r}}_{nm} As far as I understood, the unit vectors...

Hi all. I am marking GCSE paper that I did myself. There is 1 problem that I do not seems to understand. Please help me. Thank you very much. Homework Statement Daniel pulls a 3kg box up a slope from rest as shown (Attached) Given that the average friction of a slope is 2N and the speed at...

Homework Statement Suppose we walk along a unit semicircle. Homework Equations Find the average value of our distance from the base of the semicircle. The Attempt at a Solution y_{ave} = \frac{1}{1-(-1)}\int_{-1}^1\sqrt{1-x^2}\ dx = \frac{\pi}{4} OR y = \sin\theta, \qquad 0...

Homework Statement First, the problem, quoted verbatim: "Neutrons are created (by a nuclear reaction) inside a hollow sphere of radius R. The newly created neutrons are uniformly distributed over the spherical volume. Assuming that all directions are equally probable (isotropy), what is...

Many scientists have never taken IQ tests so there is a lack of statistical data, but what is a realistic estimate? Do you think 135-140 would be the average?

Homework Statement A soccer ball is kicked into the air from a platform. The height of the ball, in metres, t seconds after it is kicked is modeled by h(t) = -4.9t^2 + 13.5t + 1.2. I solved for the expression that represents the average rate of change of height over the interval 2<= t <=...

A 23.5-kg rock is sliding on a rough, horizontal surface at 9.15 m/s and eventually stops due to friction. The coefficient of kinetic friction between the rock and the surface is 0.180. What average power is produced by friction as the rock stops? I think that the way to solve it is use...