Relative Definition and 1000 Threads

Homework Statement Mary needs to row her boat across a 100-m-wide river that is flowing to the east at a speed of 1.0 m/s. Mary can row with a speed of 2.0 m/s. a) If Mary points her boat due north, how far from her intended landing spot will she be when she reaches the opposite shore? b)...

Hello When you have something and it gains a lot of mass m due to its high kinetic energy, so it gains a lot of relative energy. So, every object has its own gravitational field. So is the RELATIVE mass making a gravitatinal field? mathematically if g=GM/Rˇ2 does work, where you MUST add...

1.Two particles A and B have velocities 3i and vj respectively (in m/s). (a) Find the position of B relative to A for all t given that r (b relative to a) (t=0) = -9i+6j (in metres). (b) Find the value of v such that A and B collide. (c) If v=1 m/s, find the time and distance when A and B are...

Hello Everybody, I'm trying to plot the frequency spectrum of RIN using Matlab. I've the following code function p=rateblock tau_s = 3e-9; N0 = 1e24; A =1e-12; P0 = 1/(A*tau_s); TSPAN = 0:1e-2:10.23;; Y0 =[0 0]; [T,Y] = ODE45(@rate_equation,TSPAN,Y0); subplot(2,1,1)...

Homework Statement Locate all relative max,min,and saddle points if any. f(x,y)=x2+xy+y2-3x fx=2x+y-3 fy=x+2y Skipping some algebra I get the critical points (2,-1) fxx=2 fyy=2 d=fxx*fyy-f(x0,y0)2 d=4-9=-5 I know I'm messing up at f(x0,y0) I'm simply plugging in...

I've been wondering.. If a person (A) is, say, on top of Mt. Everest, he would be moving faster than a guy (B) at the foot of the mountain since A is further from the center of the earth, but he would also be experiencing a weaker gravitational force than B. So, for which of the invidividuals...

Can someone answer this for me please: is it possible to work out how much time has elapsed for a theoretical (and for argument's sake, mass-less) observer at the centre of the big bang whose speed of time then subsequently remained constant (rather than massively speeding up with the rest of...

I have just finished reading stuart clark's book 'The Universe' and i find myself pondering the question of space its possible infinite size,shape, and its relation to our universe. a) if space did not exist before our universe's expansion. What are we expanding into and what are we pushing...

hello everyone, Can someone kindly show me the equation for relative velocity calculations? when i search for them via wikipedia, there is only one formula for collinear objects and they move to the same direction... so what if they move opposite to each? and what if their motions...

This is totally pissing me off, I don't know what the heck am I doing wrong. Alright, so I was given a temperature of 30°C at 30% relative humidity. I have to get the absolute humidity- So I used Antoine; log(P)=7.96681-1668.21/(228+30); P = 31.6869mmHg. 0.3 x 31.6869 = 9.41517...

Homework Statement A creane lifts a 1500 kg car straight 20 m [up] How much potential energy does the car gain? How much energy does the crane transfer to the car? How much work does the crane do? The Attempt at a Solution How much potential energy does the car gain? Eg = mgh Eg =...

I'm taking AP Calc AB this year and this is a question I've come across while doing work on my own and I won't be seeing my teacher for a few days, so I' figured I'd ask some of you guys. Let's say you have an equation f(x)=(x^3)+(5x^2) and you need to find the relative minimum of that function...

In a 3D plane, there is a point with it's X,Y and Z coordonates known and a second 3D plane within the first plane with it's origins X,Y and Z coordonates relative to the parent plane origin. How do I find the X,Y and Z coordonates of that point relative to the origin of the second 3D plane...

I am not clear about the concept about relative angular velocity. So i can't solve the first question please help me

Hey Guys I am making a series of physics tutorials.. with an aim to solve problems and understand concepts without making using of any formulae by making use of animations and some real life examples I started with conceps of relative velocity.. Please tell me if its useful.. I am sorry...

Greetings, In atomic spectra experiment I came across with error propogation in the nonlinear equation: \lambda=d\times\sin(\theta) which gives the wavelength when first order constructive interference is observed at a given angle with respect to the normal of the plane of the grating. The...

Smoker Non-smoker Disease A B No disease C D Show the mathematical relationship between Relative Risk and Difference in Conditional Proportions. (Work the formulas algebraically so RR is on one side of the equation and the difference (plus some other...

Mass curves space. And speed near the the speed of light increases mass. So for someone traveling near c and is passing a partice at rest, the traveling observe feels like he's at rest and the other particle is moving. So if the other particle is moving wrt his rest frame, does he see an...

for part(i) the answer is g/4 + g/2 = 3g/4 ms^-2 how to calculate the acceleration of the 9N blcok relative to the small pulley to be g/4?? Did I miss something? thank you so much!o:)

correction -->it should be a high-level exam question. Homework Statement Two ships A and B move with constant speeds 48 km/h and 60 km/h respectively. At a certain instant ship B is 30 km west of A and is traveling due south. Find (i) the direction A should steer in order to get as close as...

If Einstein's relativity tells us that movement is relative to the observer, and if temperature is determined in the following way, movement creates friction and friction creates heat, then is temperature not relative to the observer also?

Hi. I'm reading some quantum field theory and I'm a bit rusty in my relativistic kinematics. I stumbled across the formula E_1E_2 v_{rel} = ((p_1p_2)^2 - m_1^2m_2^2)^{1/2} where 1 and 2 are two collinearly colliding paritcles with their respective masses and v_{rel} are their relative...

Homework Statement A train is passing a platform at 0.75c, and an observer, stationary and at the middle of the platform, sees two bolts of lightning simultaneously hit the front and back of the train when the train's middle was adjacent to the middle of the platform. A passenger on the train...

As the title says, imagine two observers with clocks A and B in space which move at vrel relative to each other. Just when clock A passes by clock B, the clocks counter shows zero. Observer A will conclude clock B to tick slower, while observer B will conclude clock A to move slower (both using...

Homework Statement Your car is going 78 mph on the freeway. Another car is going 58 mph in the opposite direction. How fast is the person in the other car going, relative to you? Homework Equations Your Car's Speed: 78 mph --> Another Car's Speed: <-- 58 mph The Attempt at a...

Homework Statement A mosquito flies toward you with a velocity of 2.2 km/h (E). If you are traveling toward the mosquito with a speed of 1.9 m/s, and a distance of 21.0 m separates you and the mosquito initially: A) What will your displacement be when you hit the mosquito? (7) B) How long...

A copper cylinder has a mass of 56.09g with an uncertainty of +/- 0.01g, how do I find the absolute uncertainty and the relative uncertainty? An iron sphere has measurements: Height = 2.3cm +/- 0.05 Diameter = 2.3cm +/- 0.05 Mass = 66.69g +/- 0.01 Find the volume with the correct unit...

Homework Statement A boat is capable of a constant speed of 4 m/s in a river that is flowing at 2 m/s. If the captain wishes to land 10m downriver while crossing a 50m river, then at what angle should the boat be aimed? Homework Equations...

Homework Statement A projectile is launched at 110.0 m/s at 40.0° above the horizontal off a cliff that is 250.0 m above sea level. After 4.00 s of flight, this projectile launches a second projectile at 50.0 m/s directed at 15.0° below the horizontal. a) Find the max height of the second...

Hi, What kind of sensor can be used for finding the relative position between 2 satellites? Thanks.

Hi, I have a specific question about the derivation of the relative velocity between two molecules A and B from the Maxwell Boltzmann distribution (which should equal square root of 2 times the average velocity). In equations, I have been evaluating this integral: \begin{eqnarray*}...

Homework Statement a) Find the speed of the boat with respect to the Earth. (km/h) b) Find the speed of the boat with respect to the river if the boat's heading in the water is 60° south east (km/h) Homework Equations v(x) = v cos(θ) v(y) = v sin(θ) v = √(vx^2+vy^2) but can't use it in...

Hi guys Have lurked the forums for a while but this is my first contribution. I am in first year physics at uni and I was having a discussion with my tutor regarding the relative error for an experiment (circular motion / moment of inertia). (I tried searching for an answer to this with no...

Homework Statement A swimmer heads directly across a river, swimming at 1.4 m/s relative to the water. She arrives at a point 48 m downstream from the point directly across the river, which is 74 m wide. What is the speed of the river current? What is the swimmer's speed relative to the...

Homework Statement I would like to check my answers for #3 on this practice exam: http://cyclotron.tamu.edu/dhy/sample_exam1_phys218.pdf Homework Equations The Attempt at a Solution b) v(plane-wind)x = 30cos30 v(plane-wind)y= 30sin30 + 160 c) 8.44° East of North d) 1.4...

Homework Statement When a train's velocity is 12.0 m/s eastward, raindrops that are falling vertically with respect to the Earth make traces that are inclined 30.0 degrees to the verical on the windoes of the train. A. What is the horizontal componenet of a drop's velocity with respect to the...

I'm having problems with this question. I don't know how to solve it...I've usually solved questions with some sort of resistance force but this I don't know how to solve. How would I solve this question? 1. The problem A bomber flies horizontally with a speed of 275 m/s relative to the...

Hi guys, my first post here. This isn't homework or anything, just a personal project. Homework Statement I need to find the inverse of the relative mercator equation. That is, given an origin latitude/longitude, find the current latitude/longitude from an x,y point. Because longitude is...

The lorentz-transform shows that both length and time are relative concepts. My question is: Why does both time and length have to be relative? Why can't you mathematically construct a transform which transforms your x' relative to x such that light has same speed in both the x and x' frame...

Hi all, I have a general question about relative error. Suppose that we have a vector of measurements \hat{b}=\left(\hat{b_{1}},\hat{b_{2}},...,\hat{b_{n}}\right). Furthermore, suppose that these measurements are accurate to 10%. My natural interpretation of this statement is that there is...

Homework Statement The Attempt at a Solution Do note I switched up the i, j and k vectors. I am getting half the answer correct. -7.2 is correct according to the answer key but my other solution -3.24 is clearly wrong. Does anyone know what I did wrong? I tried to be neat as...

Homework Statement Suzanne observes 2 light pulses to be emitted from the same location, but separated in time by 3μs. Mark sees the emission of the same two pulses separated in time by by 9μs. a) How fast is Mark moving relative to Suzanne? b) According to Mark, what is the separation in...

1) In the following four scenarios, determine the sign of the ball’s velocity and acceleration. Up is positive. The ball is thrown straight up. (Velocity is positive, Acceleration is negative) Up is positive. The ball is dropped straight down. (Velocity is negative, Acceleration is negative)...

Homework Statement See uploaded file. PROBLEM 5 Homework Equations See uploaded file The Attempt at a Solution I am confused on how to go about doing the rest of this I realize I can do it with the first and second derivatives but I forgot what exactly I do with that. I know the...

Suppose two observers A and B are accelerating at the same rate with respect to an inertial reference frame. In A's frame, does B move at a constant velocity? I'm pretty sure (but not certain) that the answer is yes, but even if it is I can't think of a justification.

Homework Statement A swimmer is training in a river. The current flows at 1.33 metres per second and the swimmer's speed is 2.86 metres per second relative to the water. What is the swimmer's speed relative to the shore when swimming upstream? What about downstream? Homework Equations...

Given the first N prime numbers what is the largest gap between consecutive numbers that are relatively prime to all of them? Anyone know of a fast algorithm for calculating this?

I was wondering how spacetime could be relative and quantized. It doesn't make sense to me. I am especially interested in how this works in causal dynamical triangulation. I think it is a very interesting theory, and it sometimes doesn't get enough credit. But, I can't understand how at a tiny...

Dear Physics Forum Users Commonly, the relative permittivity of liquid water is reported to be \epsilon_r = 78.0\epsilon_0, \epsilon_0 being the dielectric constant of the vacuum. For ice (solid water), \epsilon_r = 4 \epsilon_0 (heard it in a talk once). Is it correct to interpret the...

Is the wave function a "relative" wave (entanglement) Alice and Bob build a quantum entanglement experiment with the help of a lab technician. The experiment runs and a quantum entangled pair is created but unbeknown to Alice & Bob the technician puts his own measuring device in the...