Relative Definition and 1000 Threads

Homework Statement Dagwood and Blondie are driving two identical cars. Blondie is passing Dagwood at twice his speed. They apply their brakes with equal constant force and stop on the level road. Dagwood travels a distance D in a time T while braking. How long does Blondie take to stop? b) how...

Convection heat transfer rate decided by Newton's cooling law doesn't have a relative velocity between the fluid and the solid surface term. But intuitively doesn't blowing faster on a hot surface make it cool quicker?

Homework Statement To an observer not in motion in the ground, the trajectory of a projectile is described by: y = x - 10^{-3}x^2(In SI units) Where it was adopted x = 0 and y = 0 for the origin point. Determine the trajectory equation for an observer that moves at 20sqrt(2) m/s in relation to...

Hi everyone, This is really annoying me, so, I am aware of the story why oxygen was replaced with carbon-12, (because chemists were using natural occurring oxygen which was a mix of oxygen-16,17,18 and therefor was an avg?, but physicists wanted pure, isolated oxygen-16 so there was two...

Homework Statement A star as an apparent visual magnitude of 14 and an absolute visual magnitude of 14.7. I have worked out that its distance is 7 parsecs. The sun has an absolute visual magnitude of 4.8 and an effective temperature of 5800k. If the star has the same effective temperature of...

Which is more acidic H2S or H2O?And why?

Homework Statement A ferryboat, whose speed in still water is 4.00m/s, must cross a river whose current is 3.00m/s. The river runs from west to east and is 128m wide. The boat is pointed north. a) If the boat does not compensate for the flow of the river water and allows itself to be...

I was curious if anyone had ever seen information about how often one frequency of electromagnetic radiation appears in the universe compared to the other. What is the most common frequency or range of frequencies, etc? Is there a way to even estimate this?

Homework Statement What is the speed of the object (a bird) relative to the ground? We are given that a bird is flying in a spiraling path and rising on a thermal, making circles with a radius of 6m every 5s and rising strait up at a velocity of 3m/s.Homework Equations V=d/t C=2πr=d The...

A trough is 8 ft long and its ends have the shape of isosceles triangles that are 2 ft across at the top and have a height of 1 ft. If the trough is being filled with water at a rate of 11 ft3/min, how fast is the water level rising when the water is 9 inches deep?I got V=2h^2 (8)/2 V=8h^2...

Homework Statement A shuttle is orbitting around the Earth at a velocity of (7.7x10^3) m/sec. The distance between a point on the Earth to the shuttle is (6.7x10^6)m. Calculate the speed of the shuttle relative to an observer on the earth. Completely lost! I was able to solve the...

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...

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)...

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...

Problem: I'm trying to make sure i understand the following proof: Suppose we have the metric spaces (X, d) and (Y, d) with Y < X. Then A is open in Y \Leftrightarrow A = B \bigcap Y where B is an open set in X. Here is the proof I have written down: (\Rightarrow) - Assume A...

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.

Homework Statement 1)A swimmer wishes to across a swift, straight river of width d. If the speed of the swimmer in still water is u and the speed of the water is v (> u), what is the direction along which the swimmer should proceed such that the downstream distance he has traveled when he...

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...