Rotational motion Definition and 600 Threads

Homework Statement I'm stuck on two problems so I'll just write them both here. A. A 2.00kg textbook rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter is 0.150m, to a hanging book with mass 3.00kg. The system is released from rest...

A 200 g, 20-cm-diameter plastic disk is spun on an axle through its center by an electric motor. What torque must the motor supply to take the disk from 0 to 1800 rpm in 4.0s? (Given: I = ½ MR2) Relevant equations I = 1/2 MR^2 T = Ia The attempt at a...

Homework Statement A thin rod of length L stands vertically on a table. The rod begins to fall, but its lower end does no slide. (a) Determine the angular velocity of the rod as a function of the angle \phi it makes with the tabletop. (b) What is the speed of the tip of the rod just...

For the rotational motion, on my book, it says "Since w (angular velocity) is the same for all points of a rotating object, a (alpha) also will be the same for all points.w and a are properties of the rotating object as a whole." The thing that I don't get is that why velocity is the same at...

Does anyone know of any good online sites that explains topics dealing with rotational motion clearly? I'm having trouble understanding my text, so I was just wondering if any of you guys know of anything that can help. I need help understanding things such as torque, work&energy in terms of...

Hi all, I'm new to the forums, so forgive me if I'm posting in the wrong place. Strictly speaking, this isn't a "homework" question in that I'm not presenting a specific problem to be solved...But I have been assigned a project (due in a week...damn you, procrastination!) that involves...

Homework Statement Two thin rectangular sheets (0.23 m 0.35 m) are identical. In the first sheet the axis of rotation lies along the 0.23 m side, and in the second it lies along the 0.35 m side. The same torque is applied to each sheet. The first sheet, starting from rest, reaches its final...

A skater holds her arms outstretched as she spins at 120rpm. What is the speed of her hands if they are 130cm apart?

rotational motion?? Homework Statement A rider rides a motorcycle over a spherical hill with a radius of 12 meters. Show that the max speed cannot exceed 24mph or 10.8 m/s is he is to remain on the surface of the hill Homework Equations The Attempt at a Solution I am not sure...

Okay, 3 problems I can't seem to get the right answer for.. 1. A 2.30-m-long pole is balanced vertically on its tip. It starts to fall and its lower end does not slip. What will be the speed of the upper end of the pole just before it hits the ground? [Hint: Use conservation of energy.] GPE...

Homework Statement A stroboscope is a light that flashes on and off at a constant rate. It can be used to illuminate a rotating object, and if the flashing rate is adjusted properly, the object can be made to appear stationary. (a) What is the shortest time between flashes of light...

Two blocks, m1= 1kg and m2 = 2kg, are connected by a light string as shown in the figure (the figure is just shows a pulley with 2 blocks on each sides). If the radius of the pulley is 1m and its moment of inertia is 5kg*m^2, the acceleration of the system in g is: I have no idea how to do...

fig. MC2 shows a uniform 100-cm long bar of weight F w, balanced in equilibrium on a frictionless pivot. [picture a long bar and it being balanced on the point, but the point is towards the beginning of the bar with a weight to the left of it, to keep it at equilibrium] ________________...

A cube of mass M = 500 g and side length 30 mm is free to spin on an axis through the center of one face. A massless pulley on this axis has a diameter of 2r = 10 mm. A weight of m = 50 g is hung from a string wrapped around the pulley. The assembly is released from rest. (a) Find the time...

Homework Statement A turntable of radius 25 cm and rotational inertia 0.0154 kg m^2 is spinning freely at 22.0 rpm about its central axis, with a 19.5-g mouse on its outer edge. The mouse walks from the edge to the center. Find (a) the new rotation speed and (b) the work done by the mouse...

A hollow cylinder(hoop) is rolling on a horizontal surface at v = 3.3 m/s when it reaches an incline of 15 degrees. how far up the incline will it go? this was in the chapter about rotational motion but from my understanding of it, it can be solved just by taking the kinetic energy and having...

Homework Statement A 45.0 cm diameter wheel accelerates uniformly from 205 rpm to 385 rpm in 7.5 s. How far will a point on the edge of the wheel have traveled in this time? Homework Equations w=omega v=initial omega a=angular acceleration r=radius h=theta t=time s=distance...

I have two problems I am working on, and I have no idea about either Homework Statement 1. A 0.400-kg object is swung in a circular path and in a vertical plane on a 0.500-m-length string. If the angular speed at the bottom is 8.00rad/s, what is the tension in the string when the object...

Hey, I've puzzled my puzzler sore on this question for my physics assignment: A 0.50-kg ball that is tied to the end of a 1.5-m light cord is revolved in a horizontal plane with the cord making a 30° angle with the vertical. (a) Determine the ball’s speed. (b) If the cord can withstand a...

Two identical blocks, each of mass M, are connected by a light string over a frictionless pulley of radius R and rotational inertia I. One block is on a horizontal plane, one is dangling at the end of the string. The string does not slip on the pulley, and it is not known whether or not there...

Homework Statement Two disks are mounted on a frictionless vertical shaft of neglible radius. The lower disk, of mass 440g and radius 3.5cm, is rotating at 180rpm on the frictionless shaft of neglible radius. The upper disk, of mass 270g and radius 2.3cm, is initially not rotating. It...

Homework Statement A uniform, solid cylinder of mass M and radius R rotates on a frictionless horizontal axle. Two equal masses hang from light/weightless cords wrapped around the cylinder. If the system is released from rest, find: A. The tension in each cord. B. The acceleration of each...

Homework Statement (Q) A uniform marble rolls down a symmetric bowl, starting from rest at the top of the left side. The top of each side is a distance h above the bottom of the bowl. The left half of the bowl is rough enough to cause the marble to roll without slipping but the right half is...

Homework Statement A 392N wheel comes off a moving truck and rolls without slipping along a highway. At the bottom of a hill it is rotating at 25.0 rad/s. The radius of the wheel is 0.600m and its moment of inertia about its axis of rotation is 0.800MR^2. Friction does work on the wheel as it...

On his last throw of the Atlanta Olympics, Lance Deal launched the hammer 81.12m, good enough for a silver medal. The hammer is thrown by rotating the body in a circle, building up rotational speed until releasing it and letting the rotational velocity change to translational velocity. The...

Homework Statement A rotating wheel requires 3.00s to rotate 37.0 revolutions. Its angular velocity at the end of the 3.00-s interval is 98.0 rads/s. What is the constant angular acceleration of the wheel? [b]2. Homework Equations rotational kinematic equations?? The Attempt at a...

Homework Statement A disk and a box of equal mass are released from the top of two inclines both of which are a height h above the ground and make an angle θ to the horizontal. Let the radius of the disk be R. How much sooner does the box reach the bottom of the incline than the disk...

The first one: Homework Statement 1) A compact disc (CD) stores music in a coded pattern of tiny pits 10^-7 m deep. The pits are arranged in a track that spirals outward toward the rim of the disc; the inner and outer radii of this spiral are 25.0 mm and 58.0 mm , respectively. As the disc...

Homework Statement If a rotational object is moving from rest to 200rpm in .23 seconds, the acceleration is? Homework Equations a = V^2/r v = 2Pi(r)/t I am sure there are others, but this is just a General Physics I course, so its dealing with Newton and Kepler's laws. The Attempt...

would someone be able to tell me if this is right or what I've done wrong? thankyou Homework Statement a) What torque does the bicep muscle have to apply to hold the forearm of mass 1.10 kg and length 30 cm horizontally? Assume the arm is a rod of uniform mass density. b) What torque does...

Homework Statement Two Masses are suspended from a pulley. The pulley itself has a mas of .20kg a radius of .15m a constant torque of .35 MN due to the friction between the rotating pulley and its axle. What is the magnitude of the acceleration of the suspended masses if m1= .4kg and m2= .8...

Homework Statement (On a drag race car with large rear wheels and small front wheels) The front wheels in the race car help keep the vehicle from nosing upward when it accelerates. Why is this? Homework Equations The Attempt at a Solution

Homework Statement A uniform rope 12.0m long and with a mass 3.00kg is hanging with one end attached to a gymnasium ceiling and the other end just touching the floor. The upper end of the rope is released, and the rope falls to the floor. What is the change in the gravitational potential...

Homework Statement Small blocks with mass m, are clamped at the ends and at the center of a light rod of length L. Compute the moment of inertia of the system about an axis perpendicular to the rod and passing through a point one third of the length from one end. Neglect the moment of inertia...

A beginning bowler throws a bowling ball of mass M and radius R=11 cm down the lane with initial speed v0=8.5 m/sec.The ball is thrown in such a way that it skids for a certain distance before it starts to roll.It is not rotating at all when it first hits the lane,its motion being pure...

Homework Statement A uniform solid disk of radius 7.1m and mass 30.3kg is free to rotate on a fricionless pivot through a point on its rim. [picture: http://www.wellesley.edu/Physics/phyllisflemingphysics/107_p_angular_images/figure_9.gif] If the disk is released from rest in the position...

Homework Statement A block (mass = 2.4 kg) is hanging from a massless cord that is wrapped around a pulley (moment of inertia = 1.5 x 10-3 kg·m2), as the figure shows. Initially the pulley is prevented from rotating and the block is stationary. Then, the pulley is allowed to rotate as the...

An object of mass "m" is whirled with increasing speed in a horizontal circle. if the string breaks with v[SIZE="1"]0 determine the tension in the string just before the string breaks using the terms m,r(radius of circle), v[SIZE="1"]0, and g.

Hi all, this is my first post. Google has failed me, although i have learned a lot of physics in the meantime. I am not a physicist (am an evolutionary computation person). Anyway, i am building a physics simulator for an auv submersible and i wanted something cleared up :-)...

Homework Statement A 2.5 kg pulley of radius 0.15m is pivoted about an axis through its center. What constant torque is required for the pulley to reach an angular speed 25rad/s after rotating 3.0 revolutions, starting from rest? Homework Equations torque = (mr^2)(angular acceleration)...

Homework Statement From the text: "A 50 kg mass is tied to a massless rope wrapped around a solid cylindrical drum. The drum is mounted on a frictionless horizontal axle. When the mass is released, it falls with acceleration a = 3.7 \frac{m}{s^2}. Find (a) the tension in the rope and (b)...

Recently had a lab on Rotational motion and mass distribution (strange as it wasn’t covered in class yet), and there were a few questions I needed to answer. I’m doing my best to understand the lab and concept, and I was hoping that someone could possibly broaden my understanding and tell me if...

Homework Statement Two identical soccer balls are released from rest from the top of ramp consisting of a straight section connected to a circular section having the shape shown at right (height of ramp from where ball is released to bottom of curve is 4.0m. The radius of the curve is 1.5m)...

Homework Statement Two identical soccer balls are released from rest from the top of ramp consisting of a straight section connected to a circular section having the shape shown at right (height of ramp from where ball is released to bottom of curve is 4.0m. The radius of the curve is 1.5m)...

Homework Statement The flywheel of a steam engine begins to rotate from rest with a constant angular acceleration of 1.35 rad/s^2. It accelerates for 33.1 s, then maintains a constant angular velocity. Calculate the total angle through which the wheel has turned 47.5 s after it begins...

Homework Statement A bicycle has wheels with a diameter of .600 m. It accelerates uniformly and the rate of rotation of its wheels increases from 215rpm to 275rpm in a time of 24.3 seconds. Find the linear acceleration of bicycle. Homework Equations w =wi + alpha(time) The Attempt...

A thin, uniform stick of length 2.1 m and mass 4.2 kg is pinned through one end and is free to rotate. The stick is initially hanging vertically and at rest. You then rotate the stick so that you are holding it horizontally. You release the stick from that horizontal position. Remember that the...

Homework Statement A solid sphere with mass "m" and radius "r", slides (without rotating) on a frictionless horizontal surface, with speed of V[0]. At time t[0] the sphere roll on a surface with friction "u", at time t[0] the ball is starts rotating as it glides aswell. At time t[1] the...

Hello everybody. I have a rather strange question regarding the rotational motion of a solid object across an incline plane. I wonder if it is possible for a solid object to move upwards the plane without the application of any external force, other than its own weight and the friction with the...

I've attached the problem as a .jpg file. The mass obviously has potential energy. Is this simply converted to the kinetic energy of the mass plus the two kinetic energies of the pulleys? I also don't see how I would find the angular speed (probably don't even need to) of the pulleys. Cant...