Angular speed Definition and 267 Threads

Homework Statement A wheel rotating about a fixed axis has an angular position given by theta= 3.0 - 2.0t^3, where theta is measured in radians and t in seconds. What is the angular acceleration of the wheel at t = 2.0s?Homework Equations wf = w + atThe Attempt at a Solution I realize I most...

Homework Statement A playground merry-go-round of radius R=2.00m has a moment of intertia I=250kg.m^2 and is rotating at 10 rev/min (rpm) about a frictionless vertical axle. Facing the axle, a 25.0kg child hops onto the merry-go-round from the ground and manages to sit down on its edge. What is...

Homework Statement A flat uniform circular disk (radius = 2.18 m, mass = 1.22E+2 kg) is initially stationary. The disk is free to rotate in the horizontal plane about a frictionless axis perpendicular to the center of the disk. A 42.9 kg person, standing 1.29 m from the axis, begins to run...

Homework Statement Two skaters, each of mass 50 kg, approach each other along parallel paths separated by 4.0 m. They have opposite velocities of 1.7 m/s each. One skater carries one end of a long pole with negligible mass, and the second skater grabs the other end of it as she passes. The...

So I'm new to the Physics Forums and am looking for some help on this problem: Wheel A of radius r=10cm is coupled by belt B to wheel C with radius R=25cm. the angular speed of wheel A is increased from rest at a constant rate of 1.6 rad/s^2. Find the time needed for wheel C to reach an...

Homework Statement Find the angular speed of the minute hand and the hour hand of the famous clock in London, England, that rings the bell known as Big Ben Express your answers using three significant figures separated by a comma. Homework Equations The Attempt at a Solution...

Homework Statement A generator consists of a circular coil of radius 0.2 meters wrapped 10 times and is spun in a uniform magnetic field of 0.38 Tesla. It is connected (on the primary side) to a transformer with 7 turns on the primary side and 20 turns on the secondary side. If the secondary...

Homework Statement A playground merry-go-round has a radius 2.40 m and a moment of inertia 2100 kgm^2 about a vertical axle through its center, and it turns with negligible friction. A child applies an 18.0 N force tangential to the edge of the merry-go-round for 15.0 s. If the...

A turntable on a frictionless bearing has an initial angular speed of 33 1/3 revolutions per minute. The turntable platter has a mass of 1.0 kg and a radius of 30.0 cm. A spider with a mass of 1.0 gram drops onto the platter at a distance of 29 cm from the center, and begins to walk, very...

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 as shown in the figure. The clay collides with the desk tangentially to its outer rim (a totally inelastic collision) and the clay and disk begin to spin about the axis...

Hi i am preparing for the test and i have a problem with the following question. an image is attached. On a frictionless table, a glob of clay of mass 0.30 kg strikes a bar of mass 1.20 kg perpendicularly at a point 0.22 m from the center of the bar and sticks to it. If the bar is 1.34 m...

Homework Statement Disk A, with a mass of 9.0 and a radius of 90 , rotates clockwise about a frictionless vertical axle at 30 . Disk B, also 9.0 but with a radius of 10 , rotates counterclockwise about that same axle, but at a greater height than disk A, at 30 . Disk B slides down the axle...

Homework Statement (a) A certain comet of mass m at its closest approach to the Sun is observed to be at a distance r1 from the center of the Sun, moving with speed v1. At a later time the comet is observed to be at a distance r2 from the center of the Sun, and the angle between rvec2 and...

Homework Statement A 320 N sphere 0.20 m in radius rolls, without slipping, 6.0 m down a ramp that is inclined at 25° with the horizontal. What is the angular speed of the sphere at the bottom of the hill if it starts from rest? Homework Equations I sphere= (2/5)mr^2 atan=rα v=rω The Attempt...

Finding minimum angular speed?? in rpms In an old-fashioned amusement park ride, passengers stand inside a 5.5-m-diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly...

Homework Statement The pulley in system drawn below has radius 8.0 cm and mass 0.6 kg. The surface on which the 4.0 kg mass is resting is frictionless. Suppose the 2.0 kg block is released from rest...

Homework Statement You are standing on the edge of a turntable with frictionless bearings that is initially rotating when you catch a ball that is moving in the same direction (but faster than) you are moving and on a line tangent to the edge of the turntable. Assume you do not move on the...

Homework Statement The thin uniform rod in Fig. 10-52 has length 4.0 m and can pivot about a horizontal, frictionless pin through one end. It is released from rest at angle θ = 40° above the horizontal. Use the principle of conservation of energy to determine the angular speed of the rod as...

Homework Statement A cylindrically shaped space station is rotating about the axis of the cylinder to create artificial gravity. The radius of the cylinder is 82.5 m. The moment of inertia of the station without people is 3.00 x 10^9 kg m^2. Suppose 500 people, with an average mass of 70.0 kg...

Homework Statement A thin rod of length 1,5m is oriented vertically, with its bottom end attached to the floor by means of a frictionless hinge. The mass of the rod may be ignored compared to the mass of an object fixed to the top of the rod. The rod, starting from rest, tips over and...

Homework Statement Wind turbines is used to generate electricity. The length of each blade is r = 52.0 m. At t = 0, the rotor begins to turn counterclockwise, starting from rest. It speeds up at a constant rate for 60 s, until it reaches 12 revolutions per minute. Later on, it slows down from...

Homework Statement In an amusement park rocket ride, cars are suspended from L = 4.19 m cables attached to rotating arms at a distance of d = 6.05 m from the axis of rotation. The cables swing out an angle of theta = 46.7 degrees when the ride is operation. What is the angular speed of...

Homework Statement A proposed space station includes living quarters in a circular ring 61.0 m in diameter. At what angular speed should the ring rotate so the occupants feel that they have the same weight as they do on Earth? Homework Equations Angular speed = radians/second The...

Homework Statement This is a concept question rather than a homework question, so i don't have any value for the question. From the figures below, the object is turning horizontally. how do we know the object will start sliding up or sliding down at what angular velocity if there is no...

You have a weight on one end of a piece of string and you run that piece of string through a tube, and then on the other end you attach a cork. You hold on to the tube and try and keep the cork spinning at a constant radius, such that the weight stays dangling at the same height. As you increase...

Hey guys, I confused about something,please help me. I have a bullet and its diameter is 0.5 inches. its speed is 400 foot /sec. It makes one complete rotation in the gun 120 mm per turn and length of the gun is 1.5 meter. How can I calculate the rotational and angular speed? -I used a...

Hello: If a person rides on a wheel that has the same speed throughout rotation. Does this mean that magnitude of angular velocity is same throughout rotation? I think if the wheel has the same speed, then the centripetal force is equivalent throughout rotation. Now, the person decides...

Homework Statement In a cement mixer, cement, gravel, and water are mixed by tumbling in a slowly rotating drum. If the drum spins too fast, the materials stick to the wall instead of mixing. Assume the axis of rotation is horizontal. Calculate the maximum angular speed for which the...

Homework Statement The reel shown below has radius R and moment of inertia I. One end of the block of mass m is connected to a spring of force constant k, and the other end is fastened to a cord wrapped around the reel. The reel axle and the incline are frictionless. The reel is wound...

An electric fan is running on HIGH. After fan has been running of 13.2 minutes, the LOW button is pushed. The fan slows down to 98 rad/sec in 1.83 seconds. The blades of the fan have a radius of 0.62 meters and their deceleration rate is 42.3 rad/sec2. a) What was the initial angular speed of...

Homework Statement Minimum Angular Speed to start SLIPPING BEFORE ROLLING WITHOUT SLIPPING. Homework Equations A cylinder of mass M with radius r is given an angular speed of an w about an axis, parallel to its length , which passes through its centre. The cylinder is gently lowered onto...

It is desired that the outer edge of a grinding wheel 9.0 cm in radius move at a rate of 6.0 m/s. Determine the angular speed of the wheel. What length of thread could be wound on the rim of the wheel in 3.0 sec when it is turning at this rate? tell me if i started off right becuz i...

Homework Statement The figure illustrates Michelson's setup for measuring the speed of light with the mirrors placed on Mt. San Antonio and Mt. Wilson in California, which are 35 km apart. Using a value of 3.00 x 108 m/s for the speed of light, find the minimum angular speed (in rev/s) for the...

Angular Speed of Earth when... Homework Statement Determine the angular speed with which the Earth would have to rotate on its axis so that a person on the equator would weigh 75% of their present weight (Radius of the Earth is 6400 km) Homework Equations wf=2pi/T wt= mg v=wr...

Homework Statement A thin rod of lenth 1.5m is oriented vertically, with its bottom end attached to the floor by means of a frcitionless hinge. The mass of the rod may be ignored compared to the mass of and object ixed to the top of the rod. The rod, starting from rest, tips over and rotates...

Homework Statement Does anyone know anything about the sagging effect of a object with mass m rotating in a circular path at an anle of "theta" below the horrizontal? How do you find the theoretical angular speed the the object is rotating at R revs/d in t seconds at an angle of "theta"...

Homework Statement In an amusement park rocket ride, cars are suspended from L = 4.37-m cables attached to rotating arms at a distance of d = 6.09 m from the axis of rotation. The cables swing out at an angle of θ = 53.9° when the ride is operating. What is the angular speed of rotation...

Homework Statement A fairgorund target consists of a uniform circular disk of mass M and radius a that can turn freely about its diamerter which is fixed in a vertical position. Iniitally the target is at rest . A bullet of mass m is moving with speed u along a horizontal line at right...

Hello all, Im new to the site so please don't hurt me :blushing: ! My final goal is to measure linear speed of a pedal powered car, and send the speed wirelessly to my laptop which will record the speed profile. My problem is that I can't find a sensor that will measure angular...

The drawing (attached) shows the blade of a chain saw. The rotating sprocket tip at the end of the guide bar has a radius of 3.8 10-2 m. The linear speed of a chain link at point A is 6.5 m/s. Find the angular speed of the sprocket tip in rev/s. Vt= w/r 6.5= w/ .038 w=.247 rev/ sec...

Homework Statement A particle A is moving at constant tangential speed v1 = 2m/s on a circumference of radius r1 = 5m. Particle B is performing a uniform circular motion on a circumference whose radius is r2 = (2)r1. Find the tangential speed of v2 of particle B assuming that the angular...

Homework Statement A uniform disk is set into rotation with an initial angular speed about its axis through its center. While still rotating at this speed, the disk is placed in contact with a horizontal surface and released. What is the angular speed of the disk once pure rolling takes place...

Homework Statement Two people start at the same place and walk around a circular lake in opposite directions. One has an angular speed of 1.7*10-3 rad/s, while the other has an angular speed of 3.4*10-3 rad/s. How long will it be before they meet? Homework Equations w=\theta/Delta t...

A 3.0-m-diameter merry-go-round with rotational inertia 120 kg*m2 is spinning freely at 0.60 rev/s. Four 25-kg children sit suddenly on the edge of the merry-go-round. (a) Find the new angular speed in rev/s. (b) Determine the total energy lost to friction between the children and the...

Homework Statement A playground merry-go round of Radius R=2.00m has a moment of inertia I = 250 kg.m^2 and is rotating at 10.0 rev/min about a frictionless vertical axle. Facing the axle a 25.0kg child hops onto the merry go round and manages to sit down on the edge. What is the new...

Homework Statement Express each of the following in radians per second: (a) 720 ; (b) 50 ; (c) 1000 ; (d) 1 (which is the angular speed of Earth in its orbit). Homework Equations why all my answers are wrong? please help me! The Attempt at a Solution

Gyroscope-- Angular Speed, Rotational Kinematics, Precession Homework Statement A Gyro Stabilizer. The stabilizing gyroscope of a ship is a solid disk with a mass of 6.50×10^4 kg; its radius is 2.30m, and it rotates about a vertical axis with an angular speed of 500 rev/min. 1) How much...

A small 13.0-g bug stands at one end of a thin uniform bar that is initially at rest on a smooth horizontal table. The other end of the bar pivots about a nail driven into the table and can rotate freely, without friction. The bar has mass 70.0 g and is 90 cm in length. The bug jumps off in the...

In an old-fashioned amusement park ride, passengers stand inside a 4.9-m-diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes well, the...

Homework Statement What is the angular speed of the tip of the minute hand on a clock, in rad/s? Homework Equations I thought the equations needed would be angular velocity= change of theta/change in time. The Attempt at a Solution I worked on this one and am sure it has a...