Circular Definition and 999 Threads

anything is appreciated! 1. The mass of a star is 1.830×1031 kg and it performs one rotation in 37.30 days. Find its new period (in days) if the diameter suddenly shrinks to 0.850 times its present size. Assume a uniform mass distribution before and after. 2. A pulley with mass Mp and a...

physics circular motion and gravity help please :( 1. a) A solid homogeneous sphere of mass M = 4.80 kg is released from rest at the top of an incline of height H=1.35 m and rolls without slipping to the bottom. The ramp is at an angle of θ = 25.7o to the horizontal. Calculate the speed of the...

Homework Statement An object is in uniform circular motion. As the time passes by, its mass decreases. ( It has Co2 in it, and it evaporates) What will happen to the object's velocity and angular momentum? Homework Equations F = mV²/r, L = mvr The Attempt at a Solution...

Uniform Circular Motion Question Please Help! (Mechanics/Physics I) A car initially traveling eastward turns north by traveling in a circular path at uniform speed as in Figure P6.10. The length of the arc ABC is 200 m, and the car completes the turn in 34.0 s. (figure attached as...

Homework Statement A turntable is rotating at a constant angular velocity of ω = 4.0 rad/s in the direction of a clockwise fashion. There is a ten-cent coin on the turntable, at a distance of 5 cm from the axis of rotation. Consider the time interval during which the turntable is...

In my examples on Faraday's law in my book, they use a drawing of a magnet approaching a circular wire. The changing magnetic flux then induces an emf on the circle of wire, which in turn causes a current to flow. I'm wondering if a current will flow in that wire without it having an element...

Hi all, new user here and straight in with a question to help me understand something. Not sure if I'm in the right sub-forum but oh well. Regarding circular motion and centripetal acceleration, we're given the classic example of a cyclist leaning into a corner to create a general equilibrium...

Direction of force acting on a body in uniform circular motion?? Hello Sir/Ma'am I'm a a novice. I joined this forum to clear my doubts and improve my physics. Here is my question.. " We generally say, frictional force always acts in a direction, opposite to the direction of motion of a body...

Homework Statement Two particles pigs of mass ##m## and ##M## undergo uniform circular motion about each other at a separation of ##R## under the influence of an attractive force ##F##. The angular velocity is ##\omega## radians per second. Show that R = \frac{F}{\omega^2}\left( \frac{1}{m} +...

I've read so much stuff on the internet including other threads on the forum but am still confused. When a car is making a turn on a level road, WHY does the static friction point inward? From what I've learned the direction of static friction points in the direction opposing movement but the...

Homework Statement Is it possible to find a solution to the wave equation on a circular membrane such that the shape remains constant, but rotates at a fixed rate in the angular direction? Homework Equations The Attempt at a Solution I've tried separating variables, and assuming...

What is the radius of the de broglie circular orbit with n=1?

Alright, here's the problem I'm have been given: "A boy is riding a merry-go-round at a distance of 7.00 m from its center. The boy experiences a centripetal acceleration of 7.50 m/s2. What Centripetal acceleration is experienced by another person who is riding at a distance of 3.00 m from...

Homework Statement I need to find the centroid of a circular segment. I know nothing of calculus, and this is part of an analysis for statics that goes beyond the material covered in class. Homework Equations I've seen this equation for calculating the centroid...

If I was given some n(very large) points, and if I want to fit a curve circularly, I think I should go for least squares method. What is the optimal way to do it? can someone explain me clearly how to proceed using least squares method? I don't how to proceed. But I know I should do least...

I'm trying to derive the formula for the tangential acceleration of a particle undergoing circular motion a_{tan}=r\alpha using vectors in the same way you would for uniform circular motion. r is the radius and \alpha is the angular acceleration. Would it be correct to start with...

In high school whenever i asked questions about planets and their orbits around their star or the orbits of satellites around their planets ,i always got the answers with the terms centrifugal ,centripetal force and an example of a stone tied to a thread and how it behaves when you hold the...

Consider the equatorial plane of a spherically symmetric space-time. Then we can write the metric in the equatorial plane (theta=pi/2) in terms of three coordinates - [t, r, phi] ds^2 = -f(r) dt^2 + g(r) dr^2 + h(r) dphi^2 For the Schwarzschild metric we can write: f = c^2(1 -\frac{2 G...

a friend of mine asked me this question after i told her that the rainbows were a phenomenon made by the sun and the rain, and also told her, that the rainbow, in fact was a full circle, but it seems to be an arch because the other half of the rainbow is "underground" and so she asked me why it...

The post-Newtonian expansion at the first post-Newtonian 1PN level under Schwarzschild conditions, a test-body in a spherically symmetric gravitational field, gives the following expression for the gravitational acceleration of the test-body: \frac{{\rm d}\bar{v}}{{\rm...

Homework Statement A satellite is at an altitude of 3R (R- Radius of the planet) circulating around the planet with a velocity v. In order to make its path elliptical the velocity is changed from v to βv. What should be maximum value of β such that the satellite doesn't collide with the...

Homework Statement A polarized wave in the y axis, propagates in the z axis and is incident to a quarter-wave plate. Viewing the down from -z to z, the fast axis is 45deg below the x-axis. Determine the polarization of the beam immediately following the quart-wave plate. Homework...

Homework Statement A ferris wheel with a radius of 14.0 m rotates at a constant rate, completing three revolutions in 50.0 s. What is the apparent weight of a 60.0 kg passenger when she is at the top of the wheel? Given choices: 532 N, 452 N, 562 N, 625 N, 469 N Homework Equations...

Homework Statement Why does friction act towards the center when a car does uniform circular motion by itself. The Attempt at a Solution I know that centripetal force is needed to move an object in a centre and so there should be a force acting towards the center in the circular...

Homework Statement Imagine two clocks that both perform uniform circular motion of radius a in the x-y plane, but in opposite directions: xμ(u) ={t, a cos(ωt),±a sin(ωt), 0}. Suppose these clocks are synchronized to agree when they are coincident at x = a at t = 0. How much time elapses until...

Homework Statement A bird of mass 0.5kg dives and then pulls out of the dive by flying in a portion of a vertical circle of radius 15m. At the bottom of the arc the birds speed is 25m/s. a) What is the magnitude of the net vertical force acting on the bird? b) What is the magnitude of the...

Homework Statement The general quantization of motion in circular orbits is obtained by combining the equation of motion ## \frac{mv^2}{r} = |\frac{dU(r)}{dr}| ## with the angular momentum quantization condition ## mvr=n\hbar ## Use this procedure to calculate the spectrum for circular...

Homework Statement A lighthouse is located on a small island 3km away from the nearest point P on a straight shoreline and its light makes four revolutions per minute. How fast is the beam moving along the shoreline when it is 1km from P? Homework Equations The Attempt at a...

Homework Statement This is regarding the following problem: http://s24.postimg.org/bmaa4a65h/sphere_in_bowl.png Homework Equations I will be referring to this drawing: http://s22.postimg.org/6zl9mw9zj/drawin.png The Attempt at a Solution Let me just show first how I got my answer and I'll...

Hi, Say there's a particle moving with just a radial component of acceleration, this will stay in circular motion because the acceleration is always perpendicular to the velocity. But if you introduce a tangential component of velocity, according to my book the particle stays in circular...

Homework Statement At t1 = 3.00 s, the acceleration of a particle moving at constant speed in counterclockwise circular motion is a1=(6m/s2)i+(5m/s2)j At t2 = 4.00 s (less than one period later), the acceleration is a2=(5m/s2)i-(6m/s2)j The period is more than 1.00 s. What is the radius of...

Homework Statement In how many ways can a group of 9 women and 6 men be seated at a circular table if no two men can be seated next to each other? Homework Equations The Attempt at a Solution I have come up with a solution, but I'm unsure if my reasoning is correct...

Homework Statement When we keep a circular copper (ohmic) conductor at a constant temperature T_1, thermal energy is produced along it at a rate P_1 and the magnetic field at its center has magnitude B_1. Then, we heat the conductor to a higher constant temperature T_2 (i.e. T_2>T_1). At...

Homework Statement 1. Proof that the vectors \vec{t}(t) = cos(ω(t)), sin(ω(t)) and \vec{n}(t) = -sin(ω(t)), cos(ω(t)) are linearly independant 2. Proof that ω = ω\in\mathbb R 3. Can all angular velocities indicate a possible circular orbit? If so, proof it, if not which angular velocities...

Could any here smart people help me with the Lab question: 3. Why do we measure the period by timing 25 revolutions? Why not one revolution or 100 revolutions? This is from http://www2.sunysuffolk.edu/denicog/labs/lab11_132.pdf Lab from Uniform Circular motion. Thank you so much!

If electron waves weren't standing waves in Bohr's circular orbit, why and how would the waves interfere ?

I whirl a mass m attached to a wire with length L and diameter d around my head in the horizontal plane. The mass takes t seconds to move around a circle. How far do the atoms in the wire move apart, compared to their spacing at rest? Young's modulus is given. Okay, so Y = stress/strain...

Consider a circular hoop with a radius R and a mass M. Initially the centre of mass of the hoop is spinning, but not moving. Then a object with mass m is thrown at speed v by a spring-loaded gun with an angle of theta anticlockwise from the posive horizontal. Calculate the x and y components of...

1. Homework Statement : A rock of mass m is attached to a string of negligible mass and length L. The rock is released from rest from a horizontal position. When the rock is at point P, the string attached to the rock makes an angle θ with the horizontal. In terms of the quantities, m, L, θ and...

The space shuttle is moving in a circular orbit with a speed of 7.8km/s and a period of 87min. In order to return Earth, the shuttle fires its retro engines opposite to its direction of motion. The engine provide a deceleration of 6m/s^2 that is constant in magnitude and direction. What is the...

Hello, Forgive me if this question is stupid. How an object undergoes circular motion when the trajectory is not circular. I mean if it is not moving in a circle then why is it called circular motion. http://emuonline.emu.edu.tr/phys101/PhIch6pg3_files/image009.gif Let's suppose I am running...

Hi PF, What is circular convolution? Why do we need such an operation if we have linear convolution, What is its basic difference of both convolutions. Is circular convolution used only in frequency domain? -Devanand T

Homework Statement don't know the line integral latex code but; \int\underline{r}\timesd\underline{r} from (a,0,0) to (a,0,2∏b) on the circular helix \underline{r} = (acos(λ), asin(λ), bλ) The Attempt at a Solution Its the multiple use of the position vector r in the question...

Circular Motion and Static Friction Problem.. "The Wall of Death" ride Homework Statement A fairground ride called "The Wall of Death" consists of a cylindrical container of internal diameter 6.50m, mounted on a cylindrical axis. The passengers feel as if they are being pushed against the...

What I have ? Have a 16’ x 72’ rotating drum There is a solid circular sector inside the drum What I need ? Want to Calculate the torque required to move that solid circular sector from the intial position to the position shown in attached picture (90 Degrees rotation) Data ...

I am in need for some help for a lab report. The issue has happened because there is a lab of 20 students that is being led by a recently retired NASA physicist trying to lead a team of graduate student (or camel jockeys as he puts it) and the lab instructions are being botched horribly...

https://www.physicsforums.com/attachment.php?attachmentid=56184&d=1362060936 https://www.physicsforums.com/attachment.php?attachmentid=56185&d=1362060998 https://www.physicsforums.com/attachment.php?attachmentid=56186&d=1362061038 Any help of how to prove this problem would be...

Homework Statement A turntable of radius "r" is spinning counterclockwise at an initial rate of ω. at t=0, its rotation rate begins to slow at a steady pace. the rotation finally stops at t=T. At what time during the time interval 0<t<T was the magnitude of the centripetal acceleration of a...

If I have a series of pipes and containers (containing liquid) soldered together to create a circular path, and then heated at a particular point or multiple points, is it possible to somehow have the gas move in a particular direction without the gas every leaving the system? I'd prefer not to...

Homework Statement It is common to see birds of prey rising upward on thermals. The paths they take may be spiral-like. You can model the spiral motion as uniform circular motion combined with a constant upward velocity. Assume a bird completes a circle of radius 6.00m every 5.00s and rises...