Rotational Definition and 1000 Threads

Homework Statement You are asked to design an airplane propleller to turn at 2400 rpm. The forward airspeed of the plane is to be 75.0 m/s, and the speed of the tips of the propeller blades through the air must not exceed 270 m/s. What is the maximum radius the propeller can have? With this...

Hi guis, i need your help... 1. Homework Statement Evaluate the rotational and vibrational contributions to the heat capacity of a gas of DBr (D=deuterium, Br=mixture at 50% of 79Br and 81Br) at 380 K temperature, knowing that the bond distance is 1.41 Å and the vibration frequency of 1H79Br...

Homework Statement A small spherical rock of mass collides in space with a large spherical rock of mass as indicated in the diagram. After the collision the rocks stick together to form a single spherical object. https://postimg.org/image/fltmg3bj5/ (New here so I've no clue how to upload...

http://imgur.com/a/8QjoW http://imgur.com/a/8QjoW Hello- I am trying to determine the dynamics of this linearly-damped hinge. Assuming that: v(0) = 0 damping constant = b door has mass = m I was able to determine that: ∑Fx = -Fd * cos(45-θ/2) + Rx = m*dvx/dt ΣFy = -Fd * sin(45-θ/2) - Fg +...

Hi, I'm trying to program a simple physics engine from scratch as an exercise, and I'm starting with manipulating a stick with the mouse pointer. As of now, it dangles from one end demonstrating simple pendulum physics. Now, I want to add a friction component to the "axle" it's rotating on to...

I've written a space colony simulation game called High Frontier. It correctly simulates rotational stability when most of the mass is dominated by a single large spinning part. For example, a squat cylinder will be stable, but a long cylinder will end up tumbling end over end, as shown...

A flying object is moving in 3D space having translational velocity and the object is also rotating. Consider a body frame (xb-yb-zb) attached to the C.G of the moving body. Hence the body attached frame is also translating and rotating (as the object is flying) with respect to a fixed inertial...

Homework Statement For the pictured block and tackle system, formulate an equation to solve for the rotational speed of each sheave wheel for a given line pull speed. (ignore friction, slippage, line stretch) (Mass, force, efficiency, mechanical advantage are not the focus of this. Pulley...

Homework Statement So I need to move this rod with length r from point A to B as shown. It has to rotate from A to B which is 90° within 10 seconds. What I want to calculate is the torque and power required if a motor was to produce this motion (location of the motor is shown in the diagram)...

Homework Statement Find the acceleration of each object. Note: the question mark in the diagram should be θ (angle of inclined plane) 2. Homework Equations τ = F . r Στ = I . α α = a / R ΣF = m . aThe Attempt at a Solution For object A: ΣF = m . a TA - WA sin θ = mA . aA TA - mA . g. sin θ...

Linear work is F*D and rotation is 1/2Iω2, but if a problem as me rotational energy (Rotation worl = KE?) of a wheel and I have the linear work, can I just set Wrotation=Wlinear?

Homework Statement I have an angular acceleration and torque graph. I know it should be a straight line between the points, but my question is, if you extend the line toward the angular acceleration, why it doesn't go to the zero point? It is about 0,6. Homework EquationsThe Attempt at a...

Homework Statement I'm doing a question from a past paper, preparing for an upcoming exam. There is no solutions so I was wondering if my answer is correct for all parts. Take a star to be a uniform sphere with mass M_{i}=3.0 \times 10^{30} Kg and radius R_{i} = 7.0 \times 10^{8}m that...

Homework Statement A uniform thin rod of Length L and mass M is pivoted at one end is held horizontally and then released from rest. Assuming the pivot to be frictionless, find a) Angular velocity of the rod when it reaches its vertical position b) The force exerted by the pivot at this time...

Homework Statement this is a question just to help with my understanding: ... when Torque (kg m^2/s^2) and the Moment of Inertia (kg m^2) are known and used to find angular acceleration, ... T(net)/I, are the units for the resulting acceleration rad/s^2 Thanks :-) Homework Equations...

Homework Statement [/B] An ice skater executes a spin about a vertical axis with her feet on a frictionless ice surface. In each hand she holds a small 5kg mass of which are both 1m from the rotation axis and the angular velocity of the skater is 10rad/s. The skater then moves her arms so that...

Homework Statement A disk of mass m1 is rotating freely with constant angular speed ω. Another disk of mass m2 that has the same radius is gently placed on the first disk. If the surfaces in contact are rough so that there is no slipping between the disks, what is the fractional decrease in the...

Homework Statement a spool of radius R1 and R2 (R2>R1) is kept on hortizontal surface. A force f= 2t N (where t is time ) acts on the inner radius tagentially find the angular momentum of the system about the bottomost point of the spool. Homework Equations v=u+at W=Wi+alpha(t) L=IW+mvrThe...

I know that to calculate the torque about an axis, we can choose any point on that axis and find the torque about that point and take the component along the direction of the axis.Buy what is the proof behind this theorem?

Is it possible to position enough locations around the globe, that rocket thrust on the proper tangential direction might fire simultaneously and cause the Earths rotational speed to increase by some small amount ? What considerations would need to be contemplated as to how this would impact...

I was told that the direction of the cross product is an arbitary convention to give rotation a "direction" + for one direction and - for the other. That it is simply a book keeping device to make sure different rotation directions are given different signs. It seemed to be the case as I am...

So masses on springs store potential energy. Height in a gravational field store potential energy for the mass there.So why isn't there a potential energy stored inside rotating objects? Surely there are ways to translate the rotational energy to kinetic. Its kinda like a spring. If a set down a...

Homework Statement In a playground there is a small merry-go-round of radius 1.20 m and mass 220 kg. The radius of gyration is 91.0 cm. A child of mass 44.0 kg runs at a speed of 3.00 m/s tangent to the rim of the merry-go-round when it is at rest and then jumps on. Neglect friction between the...

Homework Statement Consider a uniform rod of mass 12kg and length 1.0m. At it's end the rod is attached to a fixed, friction free pivot. Initially the rod is balanced vertically above the pivot and begins to fall (from rest) as shown in the diagram. Determine, a) the angular acceleration of...

Homework Statement A child is at a playground, and chooses to try the spinning disc (see figure). The radius of the disc is 2.00 m, and the coefficient of static friction between child-surface and disc-surface is μs = 0.350. In the following questions, you must provide algebraic equations as...

Homework Statement Homework Equations Centripetal acceleration$$=\omega ^2R$$ Coriolis acceleration $$=2v_{rot}\omega $$ The Attempt at a Solution [/B] Think of the mass as lying on an incline. The forces I know are parallel to the incline are $$mgsin(\alpha), \mu N$$ Forces I know are...

I've gathered data of a skateboard going up an include and rolling back with a force plate. - Vertical force - Velocity The vertical force graph looks like this: The first bump is when the skateboard rider hits the incline. I'm doing an investigation and I don't know how this force and...

Homework Statement A 500.0-g bird is flying horizontally at 2.25 m>s, not paying much attention, when it suddenly flies into a stationary vertical bar, hitting it 25.0 cm below the top(Fig. P10.85). The bar is uniform, 0.750 m long, has a mass of 1.50 kg, and is hinged at its base. The...

Homework Statement One end of a light spring with force constant k = 100 N/m is attached to a vertical wall. A light string is tied to the other end of the horizontal spring. the string changes from horizontal to vertical as it passes over a pulley of mass M in the shape of a solid disk of...

Homework Statement Two metal disks, one with radius R1 = 2.50 cm and mass M1 = 0.80 kg and the other with radius R2 = 5.00 cm and mass M2 = 1.60 kg, are welded together and mounted on a frictionless axis through their common center, as in Problem 9.77. (a) A light string is wrapped around the...

Homework Statement A 0.23-kg turntable of radius 0.31 m spins about a vertical axis through its center. A constant rotational acceleration causes the turntable to accelerate from 0 to 26 revolutions per second in8.0 s. Calculate the torque required to cause this acceleration. Homework...

Homework Statement The system shown in (Figure 1) consists of two balls Aand B connected by a thin rod of negligible mass. Ball Ahas three times the inertia of ball B and the distance between the two balls is ℓ. The system has a translational velocity of v in the x direction and is spinning...

Homework Statement A dart of inertia md is fired such that it strikes with speed vd, embedding its tip in the rim of a target that is a uniform disk of inertia mt and radius Rt. The target is initially rotating clockwise in the view shown in (Figure 1) , with rotational speed ω about an axis...

Homework Statement A pendulum is made of a bob dangling from a lightweight string of length ℓ. The bob is pulled sideways so that the string makes an angle θi with respect to the vertical, then released. As it swings down, what is the rotational speed of the bob as a function of the changing...

Homework Statement During a certain time interval, the angular position of a swinging door is described by θ = 4.92 + 10.7t + 2.07t2, where θ is in radians and t is in seconds. Determine the angular position, angular speed, and angular acceleration of the door at the following times. first at...

Homework Statement Prove Rθ+φ =Rθ+Rφ Where Rθ is equal to the 2x2 rotational matrix [cos(θ) sin(θ), -sin(θ) cos(θ)] Homework Equations I am having a hard time trying figure our what is being asked. My question is can anyone put this into words? I am having trouble understanding what the phi...

Homework Statement Is rotational inertia an intrinsic property of an object?[/B]Homework EquationsThe Attempt at a Solution So I know that rotational inertia is a property of an object that deals with a resistance to a change in the state of rotational motion but is it an intrinsic property? I...

Homework Statement [/B] A cylinder with mass 3kg slides on ice with its base surface at 5m/s and collides with an identical but stationary cylinder. The collision is elastic. After the collision, the center-masses of the cylinders move at angles 45 and 30 degrees from the starting direction...

Homework Statement A uniform bar AB of length L is freely hinged at one end A and released from a horizontal position. a) Find the initial angular momentum. Ans: 3g/2L b)Find the angular velocity when the bar is vertical. Ans: (3g/L)^(1/2) Homework Equations momentum of inertial of a rod...

Homework Statement A wheel of diameter 45.0 cm starts from rest and rotates with a constant angular acceleration of 2.50 rad/s2 . At the instant the wheel has completed its second revolution, compute the radial acceleration of a point on the rim in two ways. 1 Using the relationship...

One end of a thin, uniform rod is connected to a frictionless hinge as shown in Figure 1. The rod has a length of 0.8 mand a mass of 2 kg. It is held up in the horizontal position (θ=90∘) and then released. 1)Calculate the angular velocity of the rod at θ=90∘. 2)Calculate the angular...

Homework Statement Use the shell method to set up and evaluate the integral that gives the volume of the solid generated by revolving the plane region about the y-axis. y = 4 - x2 y = 0 Homework EquationsThe Attempt at a Solution Okay I understand that the region is symmetric about the y-axis...

RHomework Statement A What is the velocity of the mass at a time t? You can work this out geometrically with the help of the hints, or by differentiating the expression for r⃗ (t) given in the introduction. (Figure 2) Express this velocity in terms of R, ω, t, and the unit vectors i^ and...

Homework Statement A projectile of mass m is fired from ground level with speed v0 and at angle ##\theta## with respect to the horizontal. Basically there is a projectile from start to finish, with an pivot starting at the x coordinate for the highest point on the projectile. The teacher wants...

Hello everyone, I am not an engineer, so I apologize if this is a relatively simple question. What's the best way to turn rotational motion into linear motion under the following circumstances? 1. Rotational motion is driven by a vertical bolt. 2. When turned, the bolt will extend a bar...

Homework Statement An object of moment of inertia I is initially at rest. a net torque T accelerates the object to angular velocity omega in time t. The power with which the object is accelerated is? The right answer apparently is [ I * omega^2 ] / [2 * t]. Could anyone please explain why...

1.) Homework Statement A Pulley System is shown below Find the accelerations of m1, m2 and m3 (such that there is no slipping between the disk and the rope.) Assume the threads to be massless. Homework Equations The Relevant equations i think are Newtons 2nd...

Hello, I am trying to create a mechanism that will allow for a motor to power a pendulum-like motion (but not an actual pendulum), back and forth. As shown in the picture, I need 180 degrees of rotation about the swinging part. I have researched escapement, but I need this design not to rely on...

Homework Statement This is a question I have for a presentation on rotational motion: "A solid cylinder rolls down an incline faster than a hoop [or say an open cylinder], whether or not they have the same mass or diameter. The hoop has greater rotational inertia relative to its mass than a...

1. Homework Statement A small cube is sliding on a round dish (see attached figure) . The cube is always in contact with the (vertical) edge of the dish (which prevents the cube from falling outside the dish itself). There is friction between the cube and the dish. The dish can rotate around...