Circular Definition and 999 Threads

I often hear inertia used as an explanation in areas where it seems to make intuitive sense, but appears to me to be inconsistent with the definition of inertia as just depending on an object's mass. I offer three examples (they're very similar): Example 1: An elevator Suppose an elevator...

Homework Statement Homework EquationsThe Attempt at a Solution Why can't we take the moment on the left wheel? In this case, 2d(N2) - mgd = mgd + m(v^2)h/r - mgd =m(v^2)h/r ≠ 0 Shouldn't there be an anticlockwise moment about the left wheel?

Homework Statement A train engine of mass ##m## is chugging its way around a circular curve of radius ##R## at a constant speed ##v##. Draw a free body/force diagram for the train engine showing all of the forces acting on it. Evaluate the total vector force acting on the engine as a function...

Homework Statement So, I have this problem here that's pretty basic, but the solution manual sets different axes, and I'm having a bit of trouble understanding the geometry part, meaning how he applies the given forces to the new axes. A model airplane of mass 0.750 kg fl ies with a speed...

Homework Statement http://[URL=http://www.siz.co.il/][PLAIN]http://up416.siz.co.il/up3/w2jymjm5nqxy.png [/B] A body with a mass that equals to m is inside a smooth tube and is attached to two identical springs with constants that equal to k. Their length when they are limp is L0. When the...

So, it seems there's a new twin paradox thread every day, but I don't think I've seen this particular situation looked at. The two twins move towards each other each in a circular orbit, and at one point they get close enough to each other that they can compare clocks directly (but their...

Homework Statement Homework EquationsThe Attempt at a Solution I am actually stumped by this seemingly simple problem . Since both the particles are moving , in order to calculate angular velocity of Q with respect to P looks to be difficult as the relative velocity of Q w.r.t P is...

Homework Statement A conductor consists of a circular loop of radius R and two long, straight sections as shown in the figure. The wire lies in the plane of the page and carries a current I. (a) What is the direction of the magnetic field at the center of the loop? (b) Find an expression for...

We all see pictures of the Moon, on an almost daily basis and the real thing fairly often. The craters we see are all more or less circular. There must have been a lot of very oblique impacts from all directions so why don't we see a significant number of asymmetrical impact craters? I would...

Homework Statement Hartle, Gravity, P9.8 A spaceship is moving without power in a circular orbit about a black hole of mass M, with Schwarzschild radius 7M. (a) What is the period as measured by an observer at infinity? (b) What is the period as measured by a clock on the spaceship...

Homework Statement A car moves from X to Y along a semicircular path. The radius of the path is 250 m and the time taken to complete the trip is 50 s. What is the magnitude of the average velocity and the magnitude of the average speed? can you please explain? <3 Homework Equations v = wr = 2π...

1. 2. Well, these are two pics on circular motion, i found on net... If the objects had a zero rotational motion before circular motion, and the next moment suddenly a force acts ( perpendicular to their linear momentum ) such that they move in circular motion,... which of these pictures...

:H:H:H1. Homework Statement Homework Equations equations is not needed here The Attempt at a Solution I have no idea :( Please help me![/B]

Homework Statement In the case of circular motion,the direction of the velocity is changing in every moment.So,there is a angular accelleration here.What is the direction of this accelleration? Homework EquationsThe Attempt at a Solution

Homework Statement A particle starting from rest revolves with uniformly increasing speed in a clockwise circle in an xy plane. The center of the circle is at the origin of an xy coordinate system. At t=0, the particle is at x=0.0m, y=2.0m. At t=2.0s, it has made one-quarter of a revolution and...

Suppose there is a problem such that in order to know a variable x, you have to know a variable y. But in order to know variable y, you have to know the variable x. Because of this circular dependency, wouldn't it be impossible to write any sensible equation containing x and y?

Hello, So I was reading wikipedia the other day, as I do from time to time. I came across a rather interesting sample problem posed in the article, but seeing as Wikipedia is horrible in some of their physics articles on explaining what's the hell they're doing, I became lost. Here is the...

Homework Statement A pendulum traveling at constant speed along a circular path Determine the angle that the string makes with the vertical. T[/B]he length of the string was measured to be 60 cm. The period was measured to be 1.41 s The frequency was found to be 0.709 2. Homework Equations...

Hello! I am a bit confused about Kepler 3rd law for circular orbits. So assume you have 2 bodies of masses M>m orbiting in circles around their center of mass. As the center of mass passes through the line connecting them, they must have the same period. But according to Kepler's 3rd law, this...

Question :- A car has to move on a path, that is a arc of a circle of radius (##R##). The length of the path is (##L##). Suppose it starts on the highest point of the path, find the highest uniform speed for which, it does not lose contact with the path on any point ? My attempt :- I made a...

Homework Statement Our teacher gave us a formula to solve it by creating a computer program but the problem is I'm not good at physics. I need to know what is Fc,Mr,Fk etc.. 1.) Fc = Mr(theta - Oo) ^ 2 / (t - tn) ^ 2 2.) M = Fk / Mk(m)(g)cos(theta) Homework EquationsThe Attempt at a...

Homework Statement A hockey puck with mass 200 g is attached to a rope of length 62.0 cm and swung in a horizontal circle against the ice at a rate of 58.0 rpm. Assuming the ice is frictionless, what is the tension in the rope? Homework Equations FT = mω2r The Attempt at a Solution 58rpm =...

In the figure below we put a small coin on a disc, which rotates at constant frequency f, at a distance D=0.2m by the disc rotation axis. If the coefficient of friction is μ=0.5, then what is is the maximum frequency that can have the disc so that the currency does not slip? g=10 m/sec^2 Anyone...

Why θ in radian equals arc/radius? I know that it can't be proved but there must be a explanation for this formula. How founder may have got this idea.

Homework Statement A stone tied to a string with length 1.10 m is whirled in a circle both horizontally and vertically with the same constant speed. In the vertical case the maximum tension in the string is 15.0% larger than the tension that exists when the string was horizontal. Determine the...

Homework Statement 1. A car is safely negotiating an unbanked circular turn at 21 m/s and the maximum static force acts on the tires. Suddenly a wet patch on the road reduces the static frictional force by a factor of three. At what speed must the driver slow to in order to safely continue on...

Homework Statement A small ball with mass m=1.1kg moves on the end of a string with length L=2.9. The string is anchored at point A and travels in a horizontal circle as shown. The string is at and angle of 36 degrees from the vertical. What is the string tension as the ball swings in this...

my teacher said it is the intermolecular forces between the particle but i don't agree with them so anyone can help me .

Homework Statement A particle of mass ##m## moves along a circle of radius ##R##. The modulus of the average vector of the force acting on the particle over the distance equal to a quarter of the circle is: zero if the particle moves with uniform speed ##v##. ##\dfrac{\sqrt2mv^2}{\pi R}## if...

Homework Statement "Figure 8-32 shows a pendulum of length ##L=\frac{5}{4}m##. Its bob (which effectively has all the mass) has speed ##v_0## when the cord makes an angle ##\theta_0=40°## with the vertical. (a) What is the speed of the bob when it is in its lowest position if...

Homework Statement A broken spaceship is located 10 km above the center of a large circular thin sheet of unknown dust. The sheet has a radius of 106km and a density of 7×1011kg/m2. The spaceship and the dust attract each other due to the gravitational force. a) Find the initial acceleration of...

I am curious as to the formula for radiative power due to a single object in forced circular motion. In particular, I am interested in the power of gravitational radiation for volumetric invariant mass densities for both the low density Newtonian limit and the high density general relativistic...

Homework Statement Come up with expressions for centripetal acceleration at the top of the small hump and the bottom of the loop. (this is one substep in a larger problem) Homework Equations f = ma The Attempt at a Solution Taking down to be negative, I believe that the f = ma equation at...

I need to understand something about proof by contradiction. Suppose there is an expression "a" and it is known to be equal to expression "b". Furthermore, suppose it is conjectured that expression "c" is also equal to expression "a". This would imply expression "c" is equal to expression...

Homework Statement An object of mass 0.8kg is whirled round in a horizontal circle of radius 2m with a constant speed of 15ms-1. Calculate the tension in the string. The Attempt at a Solution So far I have calculated that the angular velocity is 7.5rads-1, the frequency is 1.19Hz and the time...

[moderator's note: Thread moved from forum General Physics, so no template shown] The angular velocity of a process control motor is (10−1/2t^2) rad/s, where t is in seconds. a. At what time does the motor reverse direction? I got 4.5 s which is correct b. Through what angle does the motor...

I am having trouble understanding the concepts of vertical circular motion , though I solve all the numericals , but I think I am lacking the basic concepts of VCM. Explain how I can master this topic?

[Moderator's Note: Thread moved from forum General Physics hence no formatting template] I am trying to study Circular Motion for my exams and I'm kind of unsure about one question. The question asks what's keeping the truck in circular motion. It has to be gravity I know, but gravity being...

Lets say I have a matrix A=rand(31,51). How can I extract its elements from its center (say row = 15, column = 26) in circular manner. I want to have a matrix that displays only those elements of 'A' which are inside a circle with its center at A(15,26). Radius of circle can be any number say 5...

Homework Statement Homework Equations s=r* theta The Attempt at a Solution

Homework Statement Homework Equations s= r* theta 1/2 mv^2 = mgh energy conservation The Attempt at a Solution [/B] I think I might be having something wrong in the attempt. And how do you do using the polar coordinate approach?

Homework Statement attempt to derive the equation of centripetal acceleration using work energy theorem Homework Equations work done = Change in kinetic energy The Attempt at a Solution consider diametrically opposed points occurring in uniform circular motion - displacement = 2*R and let...

Consider a bucket filled with water in vertical circular motion. Why does there exist a contact force between water and the bucket when the bucket is at the top of center of rotation? What will happen if I remove the bottom part of the bucket when it is on the top?

circular cable i mean ?:)* Hey all second time to use this forum, hope to get same awesome help. Lets say that we have a cable in a shape of a closed perfect circle rotating in perfect conditions no air zero gravity etc around a center. The cable is 100 m circumference, rotating at 1rpm My...

Homework Statement If a curve with a radius of 88m is perfectly banked for a car traveling at 75km/h, what must be the coefficient of static friction for a car not to skid when traveling at 95 km/hr 75km/h = 20.8m/s 95km/h = 26.4m/s Homework Equations Fr=mv^2/r Fr=centripetal force m = mass r...

Homework Statement Earth is a spherical object, which completes a full rotation every 24 hours. How long should the day on Earth be so that an object at the equator is able to float freely above the ground? Homework Equations v=2πr/T Fr=mv^2/r v=velocity r= radius T = time for comleting 1...

I finally found a result I believe for the the asymptotic metric (valid for large r) of a pair of bodies in a circular orbit emitting gravitational waves. I use spherical coordinates, ##[t, r, \theta, \phi]##. If we let the linearized metric ##g_{\mu\nu}## be equal to the sum of a flat metric...

Homework Statement Evaluate \int_C \vec{F} \cdot d\vec{r} Where \vec{F} is the field generated from a circular thread of radius b in the xy plane, with magnitude j in the direction \hat{\varphi} (i.e. not along the curve, I take it) C: (x,y,z) = b(1+ \cos{\alpha}, 0, \sin{\alpha}) 3. The...

Homework Statement The potential energy of a particle of mass m is V(r) = k/r + c/3r^3 where k<0 and c is a small constant. Find the angular velocity \omega in a circular orbit of radius a and the angular frequency \omega' of small radial oscillations about this circular orbit. Hence show...

Hi, I wish to manufacture a transition tube from 4"x1" rectangular section to 3" OD circular section. The height of the part is 3" and is supposed be around 2 mm (.082") thick. Currently I am planning to manufacture this in a hydraulic press using (custom made ) end forming tools. The forming...