Circular motion Definition and 1000 Threads

Homework Statement Question 1. If two objects were in the same orbit around a planet they would both have the same orbital velocity regardless of their mass. Using the equation given, explain why an object with twice the mass experiences the same orbital velocity. Homework Equations...

We know that the magnitude of tangential component of acceleration is, atangential = dv/dt (where v is speed) So clearly atan = 0 for uniform circular motion (as v is constant) But what about non-uniform circular motion? I can see atan = 0 only when v = constant. But in non uniform circular...

Homework Statement So I just sat an exam today and I'm not sure how I did in this question. I think I did bad in it. http://www.examinations.ie/archive/exampapers/2014/LC020GLP000EV.pdf Its question 8Homework Equations F = mv^2/r v=ωr t=2(pi)r/v The Attempt at a Solution Q9 (a)...

Here is the problem I am working on: A steel ball is accelerated around a circular track of radius 72 cm from rest. after 3 circuits the ball reaches a speed of 4.00 m/s, assuming tangential acceleration, a_{T} , is constant, how long after the ball starts moving is radial acceleration, a_r ...

when the body rotates with uniform motion then the normal acceleration is V^2/r. but what is the normal acceleration when the motion is in non uniform circular motion let's say when body has uniform tangential acceleration.

Hi everyone, If you have a horizontal circular motion (with gravity action on the object), what holds the object up in the horizontal plane? All vertical components of the tension go to zero when the angle with the vertical axis is 90°... Where am I going wrong? Thanks Ramana

A interesting question came up to my mind, and it's related to the concept of different synchonization methods. If we change the synchronization parameter from 1/2 to some other value, light will have different velocities in opposite directions, which implies that two velocities with opposite...

Homework Statement The diagram shows a smooth thin tube through which passes a string with masses m and M attached to its ends. The tube is moved so that the mass m travels in a horizontal circle of radius r at constant speed v http://quickpic.info/z/yb.jpg Find an expression for M...

In introductory physics books (or at least mine) it limits the equation a_c=\frac{v^2}{r} to the sitaution where the speed around the circular path is constant. It enforces the idea that the speed is CONSTANT. But wouldn't the equation also apply to non-constant speeds? (a_c would just...

Hi all, For a marble in uniform circular motion within a smooth cone, what is the relationship between the normal force by the surface of the cone and the weight of the marble? My take is that the normal force forms a reaction pair with one of the resolved forces of weight. I have resolved the...

Q: During an earthquake, a skyscraper is designed to sway back and forth with simple harmonic motion with a period of 8 secs. The amplitude at the top floor of a particular earthquake is 70 cm. With respect to the simple harmonic motion of the top floor, calculate the following quantities: a)...

Homework Statement The minute hand of a clock is 4cm long. Find the average velocity of the tip of the minute hand between 11.00 am to 11.30 am. (in m/s)Homework Equations The Attempt at a Solution 1.In the motion between 11 am to 11.30 am, \theta=180^o=\pi \text{radiaans}\\ radius=4cm\\...

Homework Statement In a zero gravity experiment a spring has a rest length of 1.0 metre. It is attached at each end to 1.0 kg masses. The combination is then set rotating about its centre of mass at 1.0 revolution per second. Each mass undergoes uniform circular motion with a radius of 70 cm...

I was just wondering how the kinetic energy in, for example, a car undergoing circular motion is constant. We know that it's constantly acceleration due to the constant change in velocity, but surely that means that in the KE equation (1/2mv^2) the velocity is constantly changing as well. This...

I've been trying to work out the forces on a car in circular motion around a turn and I'm having trouble understanding what causes a friction force to be directed inward toward the center of the circle. I understand that on a straight path, the torque on the wheels causes them to push back...

Homework Statement Acceleration is a vector representing the rate of change of velocity. An object moving in a circle at constant speed: A. accelerates without changing its velocity B. Has constant acceleration C. Changes speed but not velocity D. Changes velocity but not speed...

Hello everyone, I'm really stuck on this question. The diagram shows an amusement park ride which contains a carriage attached to a mechanical arm. This arm spins around full circle. The carriage has a mass of 300 kg and a maximum occupancy of 300 kg. The question asks: With its carriage...

Homework Statement A small ball of mass 0.50 kg is attached to a cord and perform uniform-speed circular motion of radius 2.0 m in a vertical plane. i) If the speed of the circular motion is 10m/s, determine the tension in the cord at the lowest point of the circular motion. ii)...

Homework Statement A chemistry lab centrifuge spins creating a circular trajectory for the solutes in the test tubes with a diameter of 20cm. If an acceleration of 10 times the Earth's gravitational acceleration is required, which of the following is a minimum frequency that must be...

Hi everyone, my physics final is coming in 3 days:cry: , and I really need to have an answer to this exercise , but I'm stuck ! I don't even understand the problem statement HELP ! A typical fastball is thrwon at approximately 90 mph and with a spin rate of 113 rpm (I don't understand what it...

Homework Statement What must be the period of rotation of the Earth on its axis so that a person at the equator will have a reading on the scale that is approximately one fifth as much as he would at the North Pole? (Given on the formula sheet) Radius of Earth = 6.37 x 10^6 m Homework...

Homework Statement A steel ball of mass m is fastened to a cord of length L and released when the cord is horizontal. At the bottom of the path, the ball strikes a hard plastic block of mass M = 4m at rest on a frictionless surface. The collision is elastic. Find the speed of the block...

Hi, if I have a mass on a string and I swing it around my head at a constant speed, what is the resultant force on the mass (I'm looking for a qualitative rather than quantitive answer)? My inital thoughts were towards the centre of rotation, due to the tension on the string (and since the...

A particle of 100 grams is attached by two strings of lengths 30cm and 50cm respectively to points A and B, where A is 30cm vertically below B. Find the range of angular velocities for which the particle can describe horizontal circles with both strings taut. Take g as 10m/s^2 Answer Show...

Could anyone help my with proving that the acceleration of an object that is moving with uniform circular motion is directed towards the centre of the circle and is of magnitude ω^2(r). Thanks

Suppose that we have a body that is moving at a straight line, inertially wrt to another frame. If it starts to move in a circular way after that, what can be said about the motions of its points. Do all points have to deccelrate to achieve the circular motion, but in a different manner, since...

Homework Statement A ball of mass 125g is attached to a string .900 meters long. It is then set into vertical circular motion with 38 RPM. What is the tension of the string at the top of the circle and at the bottom of the circle? Homework Equations ∑Fy = may = marad arad = v2/R =...

Hey guys, first post here! Hoping to get a little help. Homework Statement You are a traffic safety engineer in charge of determining safe speeds for roads. A particular banked curve has a radius of 11.0 meters and is banked at an angle of 8.00°. The coefficient of static friction between...

Hello, I was asked to make experiments related to circular motion. The experiments will engage on different situations related to circular motion that we need to explain such as: -Analyzing the forces and the acceleration of a ball that moving circularly in a squared glass compared to the same...

Hi. I am a little stuck and I would appreciate some help. What is the acceleration due to gravity of the sun at the distance of 1.6 X 10^11 m? The asteroid revolves around the sun in 398 Earth days. 2. Homework Equations : F= (m*V^2)/r3. The Attempt at a Solution : First I found the...

Homework Statement A massless spring of constant k is fixed on the left side of a level track. A block of mass m is pressed against the spring and compresses it a distance d, as shown in the figure. The block (initially at rest) is then released and travels toward a circular...

Hey guys based on the Einstein train thought experiment we can say that different inertial frames disagree on simultaneity. In that specific example, the train observer is moving towards one thunder, and away from the second and in his frame the thunder in front of him occurs first followed...

Sorry if this has been asked a lot before but I did try a quick search for this but could find a simple answer. If I am at a fixed point on the equator and a friend is in a space station in a geostationary orbit, and ignoring GR, will their be time dilation between us? Or can we be...

Let's imagine a rocket orbiting the earth. The rocket could be any real rocket with moderate speed, so that relativistic effects are not significant, and also rocket does not experice notable centrifugal or other acceleration (so the rockets reference frame would appear almost inertial). A...

Homework Statement A sphere on top of a table is attached to a rope which goes through a hole in the table and is attached to a bucket at the other end. The sphere moves in a uniform circular motion with radius R. Water is then added to the bucket and the radius for the sphere's circular...

Homework Statement A 0.60 kg sphere rotates around a vertical shaft supported by two strings, as shown. If the tension in the upper string is 18 N. Calculate the tension in the lower string? the rotation rate (in rev/min) of the system? Homework Equations v=2(pi)r/T Fr= mv^2/r ω =...

My question is about the centripetal acceleration formula |a| = ω^2*r. If we keep the angular speed constant then why does increasing the radius increase the centripetal acceleration? I don't find this intuitive because the velocity vector is being turned by the same amount each second, if ω is...

I have seen the derivation of the centripetal acceleration formula a=v^2/r by saying r= rcosθi+isinθj=rcosωti+rsinωtj and differentiating twice. Since ω is constant we get a=-ω^{2}r. I've started looking at non-uniform circular motion where there is also the tangential acceleration vector...

Homework Statement Got my first physics assignment and I've been able to work out (I think) all of them except these two. 1. A conical pendulum has length 1.5m and rotates at 4ms^-1. What is its angle to the vertical? 2. A mass moves in a vertical circle attached to a fixed point by a...

Homework Statement Two spheres have a charge of q a stationary sphere between them has a charge of -q. The 2 positive spheres move like conical pendulums at a constant velocity of 12.0m/s in uniform circular motion. What is the magnitude of charge q? Homework Equations Electric Force...

Homework Statement A Centrifuge rotates at 12000rpm. What is this in radians per second? If the radius of this centrifuge is 150mm, what is the centripetal acceleration? Homework Equations v2 / r v = rω a = rω2 The Attempt at a Solution First I converted the 12000rpm...

Homework Statement Part 1 You are traveling to Jupiter's moons:Ganymede and Callisto. You have to land on the slower moon before trying to accelerate to the faster moon. Which moon will you land on first? What must your velocity be in order to "catch up"(accelerate) to the faster moon? Part 2...

I'm thinking about this: what happens if a nonuniform circular motion goes on for a long time? centripetal acceleration=tangential speed^2/r. If there is an existent tangential acceleration: tangential speed increases. So, centripetal acceleration must also increase. Therefore, after a...

Δv/v = Δr/r what is the v and r denominator? I know they both refers to velocity and acceleration respectively but exactly which vector? Base on geometric interpretation, →vector 1 + Δv = →vector 2. v is a magnitude but exactly which magnitude are we referring to? Also it states that the...

Homework Statement A car rounds a banked curve as discussed in Example 6.4 and shown in Figure 6.5.The radius of curvature of the road is R,the banking angle is θ,and the coefficient of static friction is μs. Determine the range of speeds the car can have without slipping up or down the...

Homework Statement While learning to drive,you are in a 1200 kg car moving at 20.0m/s across a large,vacant,level parking lot.Suddenly you realize you are heading straight toward the brick sidewall of a large supermarket and are in danger of running into it.The pavement can exert a maximum...

Homework Statement Homework Equations The Attempt at a Solution Why the centripetal acceleration is negative in i direction and positive in j direction?

Homework Statement Homework Equations The Attempt at a Solution I have found the solution to part(B) But I don't understand why the centripetal force is equal to the weight of the vehicle when the speed of the vehicle is maximum.

Homework Statement A smooth circular wire of radius a is fixed with its plane vertical. A small ring threaded on the wire is projected with speed u from the lowest point of the circle. Taking gravitational acceleration to be the constant g, calculate the potential energy and the kinetic energy...

Hi, I've taken a course in SR and studied GR on my own, but I do not know how to solve problems of this type. This is just purely for fun, not homework related at all. A particle of mass m is moving on a circle of radius R at constant linear velocity v = .8c. If the particle makes N...