Circular Definition and 999 Threads

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...

Homework Statement An electron is at P at t=0. It is circulating in anti-clockwise direction with a constant angular speed ω along the shown(see attachment) circular path. Magnetic field at Q (CQ=2R, where R is radius of circle) will be recorded as zero at times ....? The Attempt at a...

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...

3) Calculate the dimensions of the straight circular cone, smaller volume that can be circumscribed around a cylinder of RADIUS "R" and height "H". Answer is h = 3H and r= 3R/2

Hey everybody, no idea if this is the right place for me to post this… This is the first post I've ever written, in any forum, ever. Complete forum newbie with a complex problem, hence my desperate plea for help on this nexus of knowledge forged through experience that I have yet to gain...

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 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...

As a particle orbits around a circle, the unit vector of the velocity and acceleration component is constantly changing, so, how do I determine the unit vector?

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...

Hi all, This is probably an error resulting from my qualitative understanding of diffraction, but in most basic descriptions of the phenomena they talk about diffraction occurring when light encounters an aperture that is equal to or smaller than the wavelength of the incident light with...

Homework Statement Find direction of force on circular loop http://pokit.org/get/img/b886e52efb703d47d09fa6e781c74461.jpg What would hapend if direction of the current in a straight conductor were different ?Homework Equations ------The Attempt at a Solution...

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...

I need to find a suitable mathematical method of calculating the stresses at multiple points of a circular ring subjected to point loading. I'll calculate the rest myself- any suggestions?

Here is the question: I have posted a link there to this thread so the OP can view my work.

Homework Statement Determine the intrinsic first critical speed of a circular steel shaft supported by two bearings E=207GPa How can i determine it I'm very confused about this question , you can see the question at the attachment. Thanks for the help

1. Find the centre of mass of a semi circular plate of radius R, the density of which linearly varies with distance, 'd' at the centre to a value '2d' at the circumference. 2. Xcom = (∫xdm)/M 3. I tried attempting the solution but I am not really knowing how to get dm in terms of dx

Here is the question: I have posted a link there to this thread so the OP can see my work.

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...

Homework Statement Hey guys, I am a little bit confused how my textbook arrived at the answer it did for this particular question. The disk is in the xy-plane with radius b and uniform charge density. They go V=\frac{\rho_S}{4πε}\int_0 ^{2π}\int_0...

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...

Homework Statement Hollow circular beam with outside diameter 350mm, and wall thickness of 60mm E=60 Gpa beam length 2m Force applied to beam at midpoint of beam (1m from each end) F=200KN Force applie from the Top down, Ra , and rb from bottom up Homework Equations...

Why is the magnetic flux density uniform at the center of the circular loop ?

Homework Statement A 0.27 kg toy car is held at rest against a 1796 N/m spring compressed a distance of 8cm. When released, the car travels a distance of 112cm along a flat surface before reaching a 0.30m high loop. The friction coefficient of the flat surface and the toy car is (0.4...

Hi I'm new to this forum so still getting used to it! I have to find the moment of inertia of a circular flywheel which has radius, a and mass m! But also had area density (mass per unit area) of ρ0, Where ρ0=ρa(1+r/a) I know moment of inertia is the integral of a^2 dm and in order to...

Suppose you want to find the magnetic field at a point p at the z axis from the picture attached. Attempt to understand this problem: The way the books solves it is that it says the angle theta between current element i ds and r is 90. Then he calculates the integeral which has two...

Homework Statement A 76-kg pilot at an air show performs a loop de loop with his plane. At the bottom of the 52-m radius loop, the plane is moving at 48 m/s. Determine the normal force acting upon the pilot. Homework Equations (ƩF)R = maR = m(v2/r) The Attempt at a Solution I...

Homework Statement Designing an on ramp for the 401 the engineer wants cars to be able to make the turn with a radius of 50 m while traveling 40km/hr in conditions with no friction. What angle must he bank the curve at to make this possible? Homework Equations FR = (m)(aR) FR = (m)(v2)/(r)The...

Homework Statement I'm trying to work through an example in my classical mechanics textbook (Fowles and Cassiday, 7th ed, example 6.7.2. The problem I am having is when he expands the integrand into a power series. I'll write out the first part of the solution. The question is "find the...

Homework Statement a 0.60 kg sphere rotates around a vertical shaft supported by 2 strings, as shown. if the tension in upper string is 18N calculate. a) tension in lower string? b) rotation rate (in rev/min) of the system. Homework Equations The Attempt at a Solution...

This is the type of diagram I'm talking about...

If a ball weighing 0.2 kg is fastened at the end of a 1.5m string and is released from the horizontal position, what will the velocity be when the pendulum is at the bottom of the circle. So I was wondering if I could use energy conservation for this question because that would make it a lot...

Homework Statement Hello PF:smile:, i have a serious problem on circular motion. My textbook says that angular velocity =linear velocity /radius While the my another book specialized in physics says that angular velocity=vertical component of velocity/radius. I am not understanding if both...

Hello, I think I know how to do this question, but i'd really like to check that I'm interpreting what the question means correctly. Homework Statement The drawing shows a baggage carousel at the airport. Your suitcase has not slid all the way down the slope and is going around at a...

1. Homework Statement A bus passenger has her laptop sitting on the flat seat beside her as the bus, traveling at 10.0 m/s, goes around a turn with a radius of 25.0 m. What minimum coefficient of static friction is necessary to keep the laptop from sliding? Given: V = 10 m/s r = 25.0...

Homework Statement A body of mass 2kg performs circular motion about a point O. The radius of the circle is 0.4m and the mass completes 20 revolutions per minute.Calculate: 1) the angular veloicty. 2)the linear velocity. 3) the centripetal acceleration,and 4) the kinetic energy 5) Draw a...

Homework Statement A turntable rotates counterclockwise at 78rpm, a speck of dust on the turntable is at 0.42rad at t=0 ,What is the angle of the speck at t = 8.0s ? Your answer should be between 0 and 2π rad Express your answer using two significant figures.Homework Equations θf-θi=ωt The...

1. Homework Statement [/b] A stone mass 284g is twirled at a constant speed 12.4m/s in a vertical circle of radius 0.850m. Find the tension in the string at the top and at the bottom of the revolution. What is the maximum speed the stone can have if the string will break when the tension...

Lets say we have a ball on a string and we spin it around. The ball will undergo circular motion. The tension in the string is what provides the centripetal force, directed inwards. Then what would be the force directed outwards? (According to Newton's third law of motion). It can't be...

I am confused about connecting Newton's third law of motion to circular motion. For example, the Moon goes around the Earth in a circular orbit. There is a centripetal force (caused by gravity) that pulls the Moon inwards. However according to Newton's First law, the law of inertia, the Moon...

Homework Statement An athlete whirls a 7.00 kg hammer tied to the end of a 1.3 m chain in horizontal chain. The hammer makes one complete revolution in 1.0 s. (A) What is the centripetal acceleration of the hammer? 51 m/s2 Homework Equations ac=4pi^2*r/r^2 The Attempt at a...

Homework Statement A particle begins at rest on a circular track and is subjected to a constant angular acceleration of magnitude α beginning when t=0s.(a) Show that the magnitudes of the tangential and centripetal accelerations of the particle are equal when t=(1/α )^(1/2) Independent...

Homework Statement You want to photograph a circular diffraction pattern whose central maximum has a diameter of 1.2cm . You have a helium-neon laser (λ=633nm) and a 0.13-mm-diameter pinhole. How far behind the pinhole should you place the viewing screen? Homework Equations Y = λx/b...

1. Homework Statement A 1500 kg car drives around a flat 200-m-diameter circular track at 25 m/s. What is the magnitude and direction of the net force on the car? What causes this force? 2. Homework Equations F=mv2/r 3. The Attempt at a Solution So I suppose the net force is...

Sorry not to follow the template, but I am seeking help finding practice problems, rather than asking for help on a specific question. I am specifically searching for a practice problem regarding both projectile and circular motion/centripetal acceleration. Furthermore, I would prefer...