Rotational Definition and 1000 Threads

Homework Statement a restaurant sing hangs from a metal bar attached to a wall and supported by a wire. the bar has a mass of 5 kg, and a length of 1.2 m. the sign has a mass of 23 kg and hangs from 2 chains located at .3 m from each end of the bar. the wire makes a 28 degree angle with the...

Homework Statement An inelastic uniform solid sphere of radius 'R' is sliding without rolling over a frictionless ground with a uniform velocity 'v'. A cubical plate of height r (r<R) is fixed on the ground and the sphere impinges upon the cubical plate and rolls over it. What is the minimum...

Homework Statement A pulley with mass Mp and a radius Rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot. Mass M2 is larger than mass m1. T3 holds the pulley. The quantities Tn and g are magnitudes. (Select T-True, F-False, G-Greater...

[b]1. A rigid, massless rod has three particles with equal masses attached to it as shown below. The rod is free to rotate in a vertical plane about a frictionless axle perpendicular to the rod through the point P and is released from rest in the horizontal position at t = 0. Assume that m and d...

Homework Statement We have a rod length l with mass m. This rod is nail at its end to a wall. A putty with mass m also then collide with the rod right at the other end. The collision is perpendicular to the rod. Question is what is the minimum velocity the putty need to travel to rotate the...

Homework Statement A block of mass m = 9.00 kg is situated on an incline of angle θ = 51.0^{\circ} with coefficient of kinetic friction \mu_k = 0.200, and is connected to a light spring of spring constant k = 40.0 N/m via a light rope passing over a massive pulley as shown. The block is...

Homework Statement At a particular moment in a race, a car moving around a turn with a radius of 50m had an angular speed of .6rad/sec and an angular acceleration of .2rad/sec2 At this particular moment find: the linear speed the centripetal acceleration its total linear acceleration...

Homework Statement A centrifuge rotor is acceleratedfrom rest to 20,000 rpm in 5min. Through how many turns has the centrifuge rotor turned during its acceleration period?Assume constant angular acceleration. Homework Equations The Attempt at a Solution I just concluded that it...

Homework Statement My lab book list these four Rotational motion equations and doesn't say what they are. Could someone please tell me what each equation is and what they are used for. thanx Homework Equations \theta2-\theta1=(w1+w2)(t2-t1)/2 w2-w1=alpha(t2-t1)...

Homework Statement A solid, uniform spherical ball rolls without slipping up a hill. At the top of the hill it is moving horizontally, and then it goes over a vertical cliff. How far from the foot of the cliff does the ball land, and how fast is it moving before it lands. Use conservation...

Hi everyone, I'm having a little trouble trying to answer this problem. Here it is: A force of 22.04 N is applied tangentially to a wheel of radius 0.340 m and gives rise to an angular acceleration of 1.20 rad/s^2. Calculate the rotational inertia of the wheel. Okay so i attempted the...

Homework Statement A 7 kg bowling ball whose radius is 0.13 m is rolling directly toward you turning three times per second. What are the magnitude and direction of its rotational angular momentum about you? What is its translational angular momentum about you? Homework Equations L = r x...

Homework Statement The three 280 g masses in the figure are connected by massless, rigid rods to form a triangle. What is the triangle's rotational kinetic energy if it rotates at 6.5 revolutions per s about an axis through the center? Values given: Mass of each ball at the corner of the...

Homework Statement A bullet of mass mB = 0.0115 kg is moving with a speed of 104 m/s when it collides with a rod of mass mR = 7.93 kg and length L = 1.05 m (shown in the figure). The rod is initially at rest, in a vertical position, and pivots about an axis going through its center of mass...

A car with a weight of 10,500 N rounds a curve with a radius of 102 m on a level road at 44.0 m/s. The tires are at the point of starting to skid at this speed. a. What is the maximum force of static friction? b. What is the coefficient of static friction between the tires and the road?

Homework Statement Suppose a 5.7×10^10 kg meteorite struck the Earth at the equator with a speed 3.0×10^4 m/s, making a 45 degree angle (see figure) and remained stuck.By what factor would this affect the rotational frequency of the Earth (1rev/day)? Homework Equations It seems...

Homework Statement If a particle is projected vertically upward to a height h above the Earth's surface at a northern latitude θ, show that it strikes the ground at a point 4/3*ωcosθ*sqrt(8h^3/g) to the west. (Neglect air resistance and consider only small vertical heights.) my initial...

Case in example: If a motorbike is being riden down a steep hill and out of gear with no brakes applied; would this be more unstable than if the bike were in-gear using engine braking? (Above condition being at the same speeds).

Homework Statement In the figure, two blocks, of masses 2 kg and 3 kg, are connected by a light string which passes over a pulley of moment of inertia 4.00 E-3 kg m m and radius 0.05 m. The coefficient of friction for the table top is 0.30. The blocks are released from rest. Using energy...

Hi, I have a physics assignment due, and I've been struggling with a particular question. I would really appreciate if anyone could please help. Homework Statement Consider the system below. The mp = 20.0 kg 'pulley' is a solid uniform sphere of radius of 0.250 m with the frictionless...

Homework Statement Four identical particles of mass 0.717 kg each are placed at the vertices of a 3.11 m x 3.11 m square and held there by four massless rods, which form the sides of the square. What is the rotational inertia of this rigid body about an axis that (a) passes through the...

Homework Statement A thin plank of mass M and length l is pivoted at one end. The plank is released at 60 degrees from the vertical. What is the magnitiude and direction of the force on the pivot when the plank is horizontal. Homework Equations N/A The Attempt at a Solution So...

Homework Statement Given a bicycle that is moving at a constant speed of 15.6 m/s with a wheel radius of .32 m... A. How long will it take the wheel to rotate 19 times? B. What angle in radians will the wheel rotate in 2.33 minutes? Homework Equations theta=angular velocity*time...

Homework Statement A high-speed flywheel in a motor is spinning at 450 rpm when a power failure suddenly occurs. The flywheel has mass 36.0 kg and diameter 70.0 cm. The power is off for 34.0 s and during this time the flywheel slows due to friction in its axle bearings. During the time the...

Hi, I consider harmonic model of diatomic molecule: two atoms connected with a massless rod. Let one axis be along the rod, other two perpendicular to it. Let rotational velocity have components only trough perpendicular axes. In one book it is said that rotational energy of such diatomic...

Two boys are sliding towards each other on a frictionless, ice-covered parking lot. Jacob, mass 45kg, is sliding towards the right at 8m/s and Ethan, mass 31kg, is sliding towards the left at 11m/s along the same line. When they meet, they grab each other and hang on. (a) What is their velocity...

Homework Statement Four identical particles of mass 0.475 kg each are placed at the vertices of a 1.73 m x 1.73 m square and held there by four massless rods, which form the sides of the square. What is the rotational inertia of this rigid body about an axis that (a) passes through the...

This last problem set my professor gave has left me befuddled. I feel like I am missing some intuition to solve these problems. The book isn't helping much, as I have spent hours in it. I have a few problems that I need some kind of head start on. Homework Statement You are designing a...

Homework Statement A merry-go-round has a radius of 5 meters and an angular velocity of 1/4 pii radians per second. How long does it take the merry go round to make one revolution? How many turns per min? Homework Equations radius of 5 meters and an angular velocity of 1/4 pii radians...

Homework Statement A tradesman sharpens a knife by pushing it against the rim of a grindstone. The 35 cm diameter stone is spinning at 200 rpm and has a mass of 15 kg. The coefficient of kinetic friction between the knife and the stone is 0.20. If the stone loses 10% of its speed in 10 s of...

Homework Statement A computer disk is 8.0 cm in diameter. A reference dot on the edge of the disk is initially located at The disk accelerates steadily for 0.50 s, reaching 2000 rpm, then coasts at steady angular velocity for another 0.50 s. I have found that a_t=17 m/s^2 @ .25s a_c =...

Suppose we have a uniform disk and two forces are acting tangentially at the rim (both pointing in the same direction and parallel to each other and at diametrically opposite ends of the disk). Since the disk does not rotate the sum of torques about an axis passing thorugh the center of the...

I was bored at work and started spinning m&m's, specifically peanut butter m&m's. If I spin the candy about its minor axis it will rotate about said axis until it reaches a certain velocity and then will rotate and start spinning about its major axis and then as it slows it will rotate back...

Homework Statement The figure shows two cylinders of radius r1 and r2 rotating about their axes (along the length) with speeds \omega_1 and \omega_2 The two cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the point of...

Alright, so I am a programmer. I am writing a physics engine for a project at school and I am having a lot of trouble understanding rotational physics. As of now, the tools I have to work with are the point of collision for an object, it's velocity, it's acceleration (gravity), and it's center...

Homework Statement A motorcycle accelerates from rest, and both tires rotate without slipping. 1. Is the force exerted by the ground on the rear tire in the forward or backward direction?explain. 2. Is the force exerted by the ground on the front tire in the forward or backward direction...

Homework Statement When a carpenter shuts off his circular saw, the 10.0-inch diameter blade slows from 4740 rpm to zero in 3.00 s. A. What is the angular acceleration of the blade(rev/s^2)? GOT IT B. What is the distance traveled by a point on the rim of the blade during the...

Homework Statement The Bohr Atom The Bohr model of the hydrogen atom pictures the electron as a tiny particle moving in a circular orbit about a stationary proton. In the lowest-energy orbit the distance from the proton to the electron is 5.29 * 10^- 11 m, and the linear speed of the electron...

hi, is it correct to say that any particle or object that is invariant under rotation of 2 pi is a boson, whereas fermions need 4 pi? what is the accurate statement about this? thank you for your reply

Homework Statement The potential energy V between the two hydrogen atoms ( mH = 1.672*10^(-24) g) in a hydrogen molecule is given by the empirical expression  V = V0 [ exp(-2a(r-r0)) - 2exp(-a(r-r0))] where V0 = 7*10^(-12) erg, a = 2*10^8 cm-1, r0 = 8*10^-9 cm. (a) Estimate the...

1. A 4.5m diameter merry-go-round is rotating freely with an angular velocity of 0.70 rad/s; its total moment of inertia is 1750 kg X m/s^2. Four people standing on the ground each of 65 kg mass suddenly step onto the edge of the merry-go-round. a) What will be the angular velocity of the...

Homework Statement The figure shows two cylinders rotating about their axes, all the variables involved are shown. The two cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the point of contact but slipping finally ceases due...

Homework Statement When a car is decelerating it's speed reduces from 80 km/h to 55 km/h. In this time the wheels of car complete 55 rotations. The diameter of the wheel is 1m. Find the 1) angular acceleration of the car. 2) time taken to stop the car if it continued in same deceleration...

I know that the selection rule is : \DeltaJ = +/- 1 but our prof said that according to some quantum mechanical calculations the odd values of J are not allowed. So, the allowed transitions are : J 0 <-> 1 ; 2 <-> 3 ; 4 <-> 5... as...

Homework Statement Suppose a uniform sphere of mass M and radius R is placed on a rough horizontal surface. It rolls without slipping. We can apply 2 equations. 1) considering the torque due to frictional force about the centre of mass, fR=I(alpha) here alpha=a/R as the it is in pure...

1. Homework Statement [/b] A small block with mass m is placed inside an inverted cone that is rotating about a vertical axis such that the time for one revolution of the cone is T. The walls of the cone make an angle v with the vertical. The coefficient of static friction is between the...

Homework Statement The acceleration 'a' of the supporting surface required to keep the centre G of the circular cylinder in a fixed position during the motion, if there is no slipping between the cylinder and the support will be?Homework Equations The Attempt at a Solution The torque acting...

Homework Statement The output voltage of an a.c. generator is \emph{V}=\emph{NBA}\omegasin(\omegat). When the voltage is connected across an inductor, the rms current in the inductor is found to be 10mA. What will Be the rms current if the rotating speed of the coil inside the generator is...

if i have a three link massless manipulator (each with length l1 l2 l3) that has rotational springs at each joint, k1 k2 k3, and I apply a force on the third link, what will be the joint angles at equilibrium? do I find the lever arm to each joint and multiply that by the force to find the...

1)The torque of the weight of anybody about any vertical axis is 0. Is it always true? 2)A sphere rolls on a horizontal surface. Is there any point of the sphere which has a vertical velocity? 3) When several forces acts on a particle we take the torque of the resultant force. Is this...