Straight line Definition and 239 Threads

How would you prove that if the curvature of a 'curve' in R3 is zero that the line is straight? All I have learned about is the Serret Frenet equations which I thought only apply when the curvature is non-zero? How do you define normals/binormals in this case? I'm not sure if this is...

motion in a straight line...tough one ok, a cyclist is traveling at 10ms^-1. he sees trafic lights ahead at 108m. He carries on cycling for a time T before decelerating and stopping at the lights 16.7seconds after he first saw the lights. Calculate T Im a bit stuck because i feel this...

Homework Statement A particle traveling in a straight line is located at the point (1, -1, 2) and has speed 2 at time t = 0. The particle moves toward the point (3, 0, 3) with constant acceleration 2i + j + k. Find its position vector r(t) at time t.Homework Equations Speed = |v| The Attempt...

Simple "Motion Along a Straight Line" Problem Hi new here to PF. I have a simple physics problem but I was confused when the teacher was explaining it (he went a little too fast on this part) so I was hoping you physicians can help me out here. Homework Statement An automobile travels on a...

Homework Statement There are two questions, 1) straight line through (2, 0, 4) and (-3, 0, 9) 2) straight line y = 2x + 3, z = 7x Homework Equations r(t) = a + tb = [a1 + tb1, a2 + tb2, a3 + tb3] The book also explains how to calculate the line if b is a unit vector, but I don't...

Point charge 2.0 uC is located at X= 0, X= 0.30m , point charge -2.0uC is located at X= 0 Y= -0.30m . What are (a)the magnitude and (b)direction of the total electric force that these charges exert on a third point charge Q= 5.0 uC at X= 0.40 , Y= 0? I drew a diagram of what was...

Yesterday I thought of a math problem, and it seems very simple, as I assume the solution is, and I want to know the answer more than I want to figure it out myself. Ok imagine point A and point B. The shortest path from A to B is a straight line. Let's now go from A to B in two orthogonal...

Homework Statement The question asks me to explain why the graphs should be a straight line? We had to make a Distance vs Time^2 graphs. The Attempt at a Solution On a position x time graph If the ball is falling only way it can be a straight line if the velocity is constant , right? I...

My first post, so hope it's in the right place! If water flowing at 2 m/s in an open channel (say 2m deep by 3m wide) flows into a circle (call the entry angle 30degrees), what happens to the speed of the water? The dimensions are just examples, it's the theory I'm interested in. I know...

Hi, I am trying to connect two straight lines. I want the connecting line between them is round, so that altogether the total plot seems continuous. Can anyone help me how to do it in matlab. :shy:

Since to travel in a straight line through space time requires the subject in question to have zero change to its state of motion, ie maintain constant velocity at all times. Does this mean that the only entity to ever have and that ever will achieve a straight line through space time is light?

why the graph for the verification of inverse square law using photocell is straight line instead of a curve ? since intensity is inversely proportional to the distance then graph must be a curve, but why it is straight line ?

I have some measurements from a physics lab experiment and I am coding in Matlab a fit for the data. [Note this is not a problem with Matlab, my problem here is theory] In normal regression of statistics the RMSE is given by: s=\frac{\sigma}{\sqrt{n}} =\sqrt{\frac{\Sigma (\epsilon...

A particle moving on a straight line is described by \psi(x)=\frac{1+ix}{1+ix^2}. Where is the particle likely to be found? I took the derivative of probability density with respect to x and equated it to 0. I got my answer to be x=0.643,-0.643,1.554i and -1.554i. Please tell me whether I am...

i have an easy question i Know how to calculate the slope but how I can get all the equation I know before that the equation is -2x+2 I know how to calculate the slope it is y2-y1/x2-x1 but how can I get +2 I attach a file describing the question

Homework Statement In 1 km races, runner 1 on track 1 (with time t1 = 147.95 s) appears to be faster than runner 2 on track 2 (t2 = 148.15 s). However, length L2 of track 2 might be slightly greater than length L1 of track 1. How large can L2 - L1 be for us to still conclude that runner 1 is...

Homework Statement Consider the metric in polar coordinates ds=\frac{2}{1-r^2}\sqrt{dr^2+r^2d\phi^2} Show that the shortest path from the origin to any other point is a straight line. Homework Equations Euler-Lagrange equations \frac{\partial F}{\partial y} - \frac{d}{dx}\frac{\partial...

I was wondering if someone could explain how to compute the Least squares fit to a straight line

I was wondering if someone could explain how to compute the Least squares fit to a straight line

Homework Statement In the course of performing several trials I determined that if you have 2 charged metal spheres (with the same amount of charge on them) and they are both positively charged, then the force of repulsion between them is changed by 1/4 each time you double the distance...

Hi All, This is my first post. I am an Electronics Engineer and came by this great forum while searching something for my presently running project. Could anyone please help me with the following: I have two points A(magnitude1,phase1[deg]) and B(magnitude2,phase2[deg]) on the input side...

If an aircraft is flying in a straight line, are there no forces acting on it, or is there an upward force acting on it?

Noob question: if an atom in a vacuum releases a photon does it have a direction? Does it propagate in a straight line? My answer was always "of course!" until I read Feynman's QED and now I'm confused. What I'm trying to get my head around is the idea that light "travels all possible paths...

Homework Statement Supopose you have two infinite straight line charges lambda, a distance apart , moving at a constant speed v. How great would v have to be in order for the magnetic attraction to balance the electrical repulsion ? Work out the actual number... Is this a reasonable sort of...

Homework Statement Determine the matrix for the spatial projection perpendicular to the straight line (x1, x2, x3) = t(1, 2, 3). The vector space is orthonormal. Homework Equations The Attempt at a Solution After a trip to #math on freenode that resulted in discussions of Gram-Schmidt...

"in 4-D, the Earth orbits around the sun in a straight line" someone told me that in 4-D, the Earth actually orbits around the sun in a straight line, could someone try to explain to me how this is so? thank you

Take a look at this.. http://sunearth.gsfc.nasa.gov/sunearthday/media_viewer/flash.html Navigate > Visualizations > Mercury Transit of the Sun Why is Mercury traveling up and down vertically? I can understand on most given view points it would not be a straight line, but the line of...

Homework Statement A dog sees a flowerpot sail up and then back past a window 5.0ft (1.77m) high. If the total time the pot is in sight is 1s, find the height above the top of the window to which the pot rises.Homework Equations standard set of kinematics equations are given; V=Vo+at...

help with straight line motion! Homework Statement A bus travels in a straight line between 2 stops.The trip of 4.0km takes 6.0 minutes . The buis accelerates unniformly from rest during the first 0.50km, and thereafter it maintains a constant speed after which it slows down uniformly during...

a machinist needs to drill five holes in a circular plate. the centers of the holes must be 8.0 cm from the center of the plate and be spaced in a circular pattern equidistant from each other. How far apart (straight-line distance will the centers of the adjacent holes be placed? some help...

Homework Statement The train travels from place A to place B for one hour. Forty minutes after the departure, first train meets with second train, which departed from place B ten minutes after first train, and it’s traveling with an average speed of 40 km / h. Homework Equations What...

Homework Statement A motorist suddenly notices a stalled car and slams on the brakes, decelerating at the rate of 6.3 meters/second^2. Unfortunately this isn't good enough, and a collision ensues. From the damage sustained, police estimate that the car was moving at 13 kilometers/hour at the...

Homework Statement You allow yourself 35 minutes to drive 25 miles to the airport, but are caught in heavy traffic and average 22 miles/hour for the first 15 minutes. What must your average speed be on the rest of the trip if you are to get there on time? Express your answer in miles/hour...

Homework Statement Two divers jump from a 2.70meter platform. One jumps upward at 1.60meters/second and the 2nd steps off the platform as the first passes it on the way down. What are their speeds as they hit the water? Which hits the water first and by how much? Homework Equations Vf^2=...

A hot air balloon is rising at 16meters/second when it's passenger throws a ball straight up at 22meters/second. How much later does the passenger catch the ball? From what I understand so far, they want time. From the problem I'm given the initial velocity (Vi) of the ball, and I know my...

Why is light traveling in "straight" line? (see restrictions) Here's a question: Why is light traveling in "straight" line? Of course there will be those of you to jump on the question and say it's not a well defined one and they'd be right. For that purpose I'll restrict the question a...

Homework Statement A certain elevator cab has a total run of 197 m and a maximum speed is 307 m/min, and it accelerates from rest and then back to rest at 1.21 m/s2. (a) How far does the cab move while accelerating to full speed from rest? (b) How long does it take to make the nonstop 197 m...

I know all object in space have orbits and orbits can be changed but is it possible for rocket or a spacecraft to travel in a straight line.

it is suspected that cells in a sample are dividing so that the number of cells present at anyone time t (measured in seconds) is growing exponentially according to the relationship y = 64 x 2^2t. it would be hard to check this relationship accurately by plotting measurements of y against t, so...

1. Homework Statement A helicopter 8.50 m above the ground and descending at 3.50 m/s drops a package from rest (relative to the helicopter). Just as it hits the ground, find a) the velocity of the package relative to the helicopter and b) the velocity of the helicopter relative to the...

Homework Statement My teacher assigned a lab report on an experiment where 2 graphs need to be drawn. One graph has some uncertainty which is calculated alright ((slope max - slope min) * 0.5) and the other graph still need to be drawn.. The values of the second graph make a perfect straight...

What is the value of q/m for a particle that moves in a circle of radius 6.2 mm in a 0.56 T magnetic field if a crossed 220 V/m electric field will make the path straight? q/m=2v/(br)^2 This was given to us in our lab and i plugged everything in and it doesn't turn out right...

To the moderator: This isn't a HW question, but it probably sounds like one, so I appologize. Please move this to the HW forum if need be. I have an integration domain inside three intersecting curves. Two of the curves are straightlines and the third is a parabola. These three boundaries...

Hi, I have a graph with a frequency on the x-axis and power density on the y axis. Both scales are logarithmic, and the graph shows a straight line between the points (110Hz, 0.001V^2/Hz) and (200Hz, 0.004V^2/Hz). I need to work out the area under this portion of the graph as it relates to...

Straight line! help! Homework Statement the straight line 3y-x-k=0 is the normal to the curve y=4x3+12x2+9x-1 at point A. The curve has two turning points. a)find the coordinates of A b)find the coordinates of the turning points of the curve. then, determine whether the turning points are...

At the instant the traffic light turns green, a car that has been waiting at an intersection starts ahead with a constant acceleration of 3.15 . At the same instant a truck, traveling with a constant speed of 18.0 , overtakes and passes the car. Part A: How far beyond its starting point does...

Homework Statement In an experiment, one of the forces exerted on a proton is F=<-ax2,0> where a =12N/m2. Calculate the work done by this force as the proton moves along a straight-line path from the point ri=<0.10m,0> to the point rf=<0.30m, 0.40 m> Homework Equations I'm not sure if I...

Homework Statement An oil tanker's engines have broken down, and the wind is blowing the tanker straight toward a reef at a constant speed of 1.5 m/s. When the tanker is 500 m from the reef, the wind dies down just as the engineer gets the engines going again. The rudder is stuck, so the only...

Homework Statement An oil tanker's engines have broken down, and the wind is blowing the tanker straight toward a reef at a constant speed of 1.5 m/s. When the tanker is 500 m from the reef, the wind dies down just as the engineer gets the engines going again. The rudder is stuck, so the only...

A car starts from rest and accelerates at a constant rate in a straight line. In the first second, the car covers a distance of 2.0 m. How fast will the car be moving at the end of the second second? Xo(1) = 0 X(1) = 2.0 m Vo(1) = 0 V(1) = 2.0 m/s t(1) = 1.0 s Thus, V(1) = Vo(1) +...