Angular speed Definition and 267 Threads

Homework Statement A horizontal bar with a mass of 3.2 kg and a length L of 64 cm is rigidly mounted to a vertical spindle of negligible mass such that the two objects spin together. The spindle has a diameter of 2.0 cm, and it is attached to the bar a distance of L /4 from its centre of mass...

Homework Statement Starting from rest, a spinning compact disk undergoes an angular acceleration of 5.0 rad/s^2. What is the angular speed of the disk after 3 revolutions? Homework Equations a=Δω/Δt ω=Δθ/Δt The Attempt at a Solution I do not understand how to solve this equation when I am not...

Homework Statement Homework EquationsThe Attempt at a Solution If I interpret "magnitude of displacement of CM per sec " as Velocity of CM ,then Horizontal Impulse provided to the rod = J ##J = MV_{cm}## Angular impulse about the CM = JL/2 ##\frac{JL}{2} = I \omega ## ,where ##I =...

Hi, I've been wondering is there anyway of calculating the angular speed of a ball after there is a collision of it and another mass. For example a baseball bat hitting the ball. I have not looked up on angular momentum, but is angular momentum involved in this? Based on common sense, I think...

Homework Statement A circular turntable of mass 2.0 kg and radius 6.0 inches is rotating freely at 66 2/3 rpm. If a 500 gram blob of clay is dropped on the disk at a distance of 4.0 inches from the center, what is the resulting angular speed of the system? Treat the clay as a point mass (I =...

Question: A streetcar is freely coasting (no friction) around a large circular track. It is then switched to a small circular track. When coasting on the smaller circle its speed is: a) greater b) less c) unchanged Relevant Formulas: w = v/r KE = 1/2mv2 My teacher said the normal force from...

Homework Statement http://imgur.com/jcZRQdu Homework EquationsThe Attempt at a Solution So I know how to solve this with conservation of energy, but I can't seem to get the correct answer using kinematic equations. τnet = Iα = (MR2*(a/R)) -Tension = MRa Fnet = ma w-Tension = ma -Tension =...

A solid balsa cube of side length L = 16.0” and mass M = 8.60 kg is at rest on a horizontal table top. It is constrained to rotate about a fixed and frictionless axis, AB, along one edge of the cube. A bullet of mass m = 50.0 g is fired with speed v at the other side of the cube, at height a =...

Homework Statement A ball with the mass m is attached to a rod, suspended by two strings both with lengths L. The rod is rotating with the angular velocity ω and the ball rotates with it in such a way that the strings are taut and the ball moves in a circular pattern. I tried to draw it on my...

Homework Statement A race car makes two laps around a circular track in 3.8 minutes. What is car's average angular speed?

1. Relevant information A bob of mass 0.5kg is attached to one end of a light inextensible string of length 0.500 m, whose other end is attached to a fixed pivot. The bob performs uniform circular motion in a horizontal plane, with the string making an angle of 30.0° with the vertical. 2...

Homework Statement The propeller blades of an airplane are 4.0 m long. The plane is getting ready for takeoff, and the propeller starts turning from rest at a constant angular acceleration. The propeller blades go through two revolutions between the fifth and the eighth second of the rotation...

Homework Statement A disk of radius 0.41 m and moment of inertia 2.8 kg·m2 is mounted on a nearly frictionless axle. A string is wrapped tightly around the disk, and you pull on the string with a constant force of 52 N. What is the magnitude of the torque? torque = 21.32 N·m After a...

Homework Statement A torque acts on a wheel rotating at 19.8 rad/s and increases its angular speed to 23.5 rad/s in 11.2 s. Find the angle through which the wheel turns during this time. Homework Equations omega = theta/time The Attempt at a Solution 23.5 - 19.8/11.2 = .33rad/s/s --- this is...

1. The problem states: Problem 9-72a: The system shown in the figure below consists of a m1 = 4.24-kg block resting on a frictionless horizontal ledge. This block is attached to a string that passes over a pulley, and the other end of the string is attached to a hanging m2 = 2.12-kg block...

Here's the problem: Two particles of mass $m$ and $M$ undergo uniform circular motion about each other at a separation $R$ 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} + \frac{1}{M}...

Homework Statement In a water vortex formed in a plastic bottle, what is the relationship between the angular speed of the water and the diameter of the hole in the cap? I would have expected that according to the conservation of angular momentum, the smaller the hole the faster the water speed...

Homework Statement You have a loop of wire (dimensions c and d) which is oriented vertically on the y-axis (the y-axis splits the rectangle in two equal pieces), and rotates about the y-axis at constant angular ##\omega##. The magnetic field is in the +i direction. What would be the torqque...

Homework Statement A ball of clay of mass m travels with velocity v in a path tangent to a disk of radius R and mass M. The clay collides with the disk tangentially to its outer rim (a totally inelastic collision) and the clay and disk begin to spin about the axis. What is the final angular...

When being burned in a writable CD-R Drive, the angular speed is often faster when playing audio... When writing along the outer edge, the angular speed of one drive is about 4800 RPM (Revolutions per minute). Find the linear speed. The question above it, or before this one was with CD's radius...

Homework Statement Exactly one turn of a flexible rope with mass m is wrapped around a uniform cylinder with mass M and radius R. The cylinder rotates without friction about a horizontal axle along the cylinder axis. One end of the rope is attached to the cylinder. The cylinder starts with...

Homework Statement You hang a thin hoop with radius R over a nail at the rim of the hoop. You displace it to the side (within the plane of the hoop) through an angle β from its equilibrium position and let it go. What is its angular position when it returns to its equilibrium position (use...

Homework Statement Use the conservation of energy law to find the speed of the blocks and the angular speed of the pulley when the heavier block hits the ground. The system starts at rest. (going to include picture) http://i.imgur.com/CjB3gzK.jpg Homework Equations Moment of inertia for...

Angular Velocity After Bullet Hits Cylinder Homework Statement A 11.0g bullet is fired at 378.1m/s into a solid disk of mass 19.1kg and a radius 0.250m. The disk is initially at rest and is mounted on fixed vertical axis that runs through it's center of mass. The line of motion of the...

Homework Statement You are consulting for an amusement park that wants to build a new "Rotor" ride. In order to increase capacity, they would like to build a unit with a 14.2-ft diameter. The Rotor should provide a centripetal acceleration of 3g. What must be the angular speed in revolutions...

Homework Statement ---Find Angular Speed--- Homework Equations I = 1/2 mR^2 Ug = mgdsinθ Us = 1/2 kd^2 KE = 1/2 I w^2 The Attempt at a Solution Moment of inertia of reel = 1/2mR2 Kinetic energy of the reel = 1/2 mv2 = 1/2(1/2mR2) w2 KE = mgdsinθ (potential due to gravity) +...

Homework Statement A block of mass m = 4 kg hangs from a rope that is wrapped around a disk of mass m and radius R1 = 27 cm. This disk is glued onto another disk of again the same mass m and radius R2 = 66 cm. The two disks rotate on a fixed axle without friction. If the block is released at a...

two pulleys connected by a belt have 15cm and 8cm radius The larger pulley rotates $25$ times in $36$ sec, Find the angular speed of each pulleey in radians per second. the 15cm pulley has circumferce of $30\pi$ so $\displaystyle\frac{25\text { rev}}{36 \text {sec}} \cdot\frac{30\pi\text{...

Homework Statement You hang a thin hoop using radius R over a nail at the rim of a the hoop. You displace it to the side (within the plane of the hoop) through angle β from its equilibrium position and let it go. Using U = M*g*y[SIZE="1"](center of mass), what is the angular speed when it...

mass of color wheel is 133.4g and raidus is 12.7cm. The moment of inertia for disk is I = (1/2)mr^s. We used strobescope and color wheel and measured the time of how long it took till color wheel's yellow part looked stop. It took 2.1s for speed up and 1.5 second for speed down. Maximum value we...

Friction as B times angular speed??! Hi, My control systems book uses a weird notation for the moment caused by friction in a rotating motor. The equation is Tfriction = B×dθ/dt Where does this equation come from? The author assumes the reader is already familiar with this equation...

A 60kg skater begins a spin with an angular speed of 6.0 rad/s. By changing the position of her arms, the skater decreases her moment of inertia by 50%. What is the skater's final angular speed? I(initial)ω(initial) = I(final)ω(final) I used 60 kg as my inertia, is inertia and mass...

Homework Statement A constant force of 50 N is applied tangentially to the rim of a solid disc with a 60cm radius. The wheel has a moment of inertia of 40 kg m^2 a) what is the mass of the disc? b) 4 seconds after starting from rest, what angular speed does it have? c) How many...

Homework Statement Water falls onto a water wheel causing it to rotate. Consider an instant when the water wheel is initially motionless and then 100 kg of water hits tangent to the wheel at a radius of 2 m (this water can be treated like a point mass). If the moment of inertia of the water...

In the figure, two skaters, each of mass 48.1 kg, approach each other along parallel paths separated by 2.90 m. They have opposite velocities of 1.61 m/s each. One skater carries one end of a long pole of negligible mass, and the other skater grabs the other end as she passes. The skaters then...

Haven't done much work with gyroscopes, so I think I'm just missing something obvious, but since I'm using very basic formulas, I cannot see my error. The stated answer is 1.8*10^3 rev/min, so I am clearly off.

Homework Statement A uniform rod (length = 2.0m) is mounted to rotate freely about a horizontal axis that is perpendicular to the rod and that passes through the rod at a point of 0.5m from one end of the rod. If the rod is released from rest in a horizontal position, what is the angular...

Homework Statement Hiya boys, Sorry i don't know how to proceed with this problem can anyone help me solve these two questions? In preparation for building a space station, an astronaut removes a self-telescoping uniform rod from the cargo bay and releases it, not noticing that he gave...

The problem I am working on is: "A student sits on a freely rotating stool holding two dumbbells, each of mass 2.97 kg (see figure below). When his arms are extended horizontally (figure a), the dumbbells are 0.95 m from the axis of rotation and the student rotates with an angular speed of...

The angular speed of the turntable with a woman on it? Help! Ok so I understand part a (why it's counterclockwise. τ = Fr = (mg)(2) = (70)(9.8)(2) = +1372) Part b is where I'm stuck... This is what I did... PEinitial + KEinitial rotational = PEfinal + KEfinal rotational PEinitial =...

What is given: Torque: τ = 34.5 N * m Inertia: I = 0.130 kg * m2 Angular speed: ω = ? Work done by a constant Torque: τΔθ = (1/2)Iωf2 - (1/2)Iωi2 Angular displacement: Δθ = 17.1 rev/s = 107.442 rad/sτΔθ = (1/2)Iωf2 (34.5)(107.442) = (0.5)(0.130)ωf2 3706.765 = 0.065ωf2 57027.156 = ωf2 238.8 = ω...

Urgent help needed with finding angular speed? This is impossible! I've even asked on Y!A and THEY all got it WRONG. Webassign says the answer is 32.9 but how? This is so freaking frustrating...anlfdsfjlkdjf Ok...so what I tried doing was ask myself what the equation for angular speed was.ω...

Use conservation of energy to determine the angular speed of the spool shown in the figure below after the 3.00 kg bucket has fallen 4.40 m, starting from rest. The light string attached to the bucket is wrapped around the spool and does not slip as it unwinds. I initially thought this...

Homework Statement A merry-go-round rotates at the rate of 0.12 rev/s with an 86 kg man standing at a point 1.4 m from the axis of rotation. What is the new angular speed when the man walks to a point 0 m from the center? Consider the merry-go-round is a solid 45 kg cylinder of...

Homework Statement A constant torque of 25.5 N · m is applied to a grindstone whose moment of inertia is 0.117 kg · m2. Using energy principles, and neglecting friction, find the angular speed after the grind- stone has made 14.6 rev. Answer in units of rad/s Homework Equations 1...

Homework Statement A uniform stick 1.2 long with a total mass of 240 is pivoted at its center. A 3.1- bullet is shot through the stick midway between the pivot and one end The bullet approaches at 250 and leaves at 140 . Homework Equations The Attempt at a Solution

Homework Statement A metal sphere is attached to the end of a string and then set in motion such that it rotates in a horizontal circle as shown in the sketch. The metal sphere has a mass of 0.5kg and the radius of the circle is .2m. 1)Find the tension in the string 2)Calculate the radial...

Homework Statement Under some circumstances, a star can collapse into an extremely dense object made mostly of neutrons and called a neutron star. The density of a neutron star is roughly 10^{14} times as great as that of ordinary solid matter. Suppose we represent the star as a uniform, solid...

[SOVLED] Angular speed of rod after projectile collides into it Homework Statement Homework Equations L = r x p Iparallel = ICM + md2 The Attempt at a Solution L = r x p = mvir = mvid/2 mvi(d/2) = (Iparallel + md2)ω mvi(d/2) = (1/12M(d/2)^2 + m(d/2)^2)ω Plugging and solving...

Homework Statement . The angular speed of an automobile engine is increased at a constant rate from 140 rad/s to 200 rad/s in 20 s. The number of radians through which the engine turns during this 20-s interval is Homework Equations The Attempt at a Solution I didnt know...