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Torques

Forces and Torques: Net torque applied to the cable car.

In San Francisco a very simple technique is used to turn around a cable car when it reaches the end of its route. The car rolls onto a turntable, which can rotate about a vertical axis through its center. Then, two people push perpendicularly on the car, one at each end, as in the drawing. The turntable is rotated one-half of a

Forces and Torques

You are installing a new spark plug in your car, and the manual specifies that it be tightened to a torque that has a magnitude of 47 Nm. Using the data in the drawing, determine the magnitude F of the force that you must exert on the wrench.

Torque on a loop

A rectangular wire loop with a cross-sectional area of 5,000 cm^2 carries a current of 0.50 amperes. The loop is free to rotate about an axis that is perpendicular to uniform magnetic field strength of 0.40 Tesla. The plane of the loop is initially at an angle of 25 degrees to the direction of the magnetic field. What is the ma

Angular acceleration of the rod

In problem 16.72(a), if the uniform slender rod weighs 15 lb, and the horizontal force P is 12 lb, the angular acceleration of the rod is: a. 44.2 rad/s^2 b. 82.8 rad/s^2 c. 55.2 rad/s^2 d. 35.2 rad/s^2

Application of the Principle of Conservation of Angular Momentum

A student on a piano stool rotates freely with an angular speed of 3.16 rev/s. The student holds a 1.50 kg mass in each outstretched arm, 0.794 m from the axis of rotation. The combined moment of inertia of the student and the stool, ignoring the two masses, is 5.45 kg*m2, a value that remains constant. As the student pulls his

Rotational Axes and Maximum Stresses

See the attached file. 1. Two solid aluminum shafts (G = 3.7x106 psi) are connected by the gears shown. Ends B and D are fixed. What is the angle through which end C rotates? 2. For the beam of the cross section shown, determine the location of the neutral axis from the bottom of the beam. 3. For the beam of question

Three problems on torque

1. At the local playground, a 16 kg child sits on the end of a horizontal teeter-totter, 1.5m from the pivot point. On the other side of the pivot an adult pushes straight down on the teeter-totter with a force of 95 N. In which direction does the teeter-totter rotate if the adult applies the force of a distance (a) 3.0 m, (b) 2

Rotational Dynamics

Please help with the following problem. By means of a rope whose mass is negligible, two blocks are suspended over a pulley, as the drawing shows. The pulley can be treated as a uniform solid cylindrical disk. The downward acceleration of the 44.0-kg block is observed to be exactly one-half the acceleration due to gravity. N

Rotational Motion: Wheel is pulled on a curb.

(See attached file for full problem description with diagram and values) --- You are trying to raise a bicycle wheel of mass and radius up over a curb of height . To do this, you apply a horizontal force . 1. What is the least magnitude of the force that will succeed in raising the wheel onto the curb when the

Torque and potential energy in a current carrying coil

4) A circular coil with area A and N turn is free to rotate about a diameter that coincides with the x-axis. Current I is circulating in the coil. There is a uniform magnetic field B in the positive y-direction. Calculate the magnitude and direction of torque and the value of the potential energy U, as given in the equation; "U

For and troque acting on a current carrying coil

3. A rectangular coil of wire, 22.0 cm by 35.0 cm and carrying a current 1.40 A, is oriented with the plane of its loop perpendicular to a uniform 1.50 T magnetic field as shown below. a) Calculate the net force and torque which the magnetic field exerts on the coil. b) The coil is rotated through a 30.0º angle about the axis

Torque and angular acceleration

Find the mass of a uniform solid cylinder which is mounted so that it can rotate freely (i.e., without friction) about a fixed axis that passes through its center and runs along the length of the cylinder. This is not a simple project because for one thing, that cylinder is heavy! Also you don't want to risk removing the heavy c

Angular Acceleration of a Roller

A roller is rolled by pulling on a rope wrapped around an inner groove, as shown in attachment. If the roller rolls without slipping, the angular acceleration in rad/sec^2 of the roller is what? (See attached file for full problem description)

Circular Frequency of a Rod

A slender rod is pivoted at 0 which is a frictionless bearing. The circular frequency in rad/s at the rod for a small oscillation is? (See attached file for full problem description)

Physics Problem - A uniform, hollow, cylindrical spool

Please help with the following classical mechanics problem. See attached file for full problem description. --- A uniform, hollow, cylindrical spool has inside radius R/2, outside radius R and mass M as in the attached .jpg. It is mounted so that it rotates on a fixed horizontal axle. A counterweight of mass m is connecte

Motor Torques

Q1) Assume the torque stays constant at 120 N-m. How long will it take for the unloaded armature to accelerate from zero up to full speed of 3000 rpm? Now I am given the formular Ix = I w-wo / t. All I know is that the rotational inertia is 2.81 kg-m^2. Q2) What will be the power of the motor when it is s

Dipole Moments

Please show all work and show all equations used so I can understand completely. 1) A uniform electric field of 300N/C makes an angle of 25 degrees with the dipole moment of an electric dipole. If the torque exerted by the field has a magnitude of 2.5*10^-7N.m, the dipole moment must be ___? 2) The dipole moment of a dip

Solving a Rigid Body Problem Using Newton's Second Law of Motion

See the attached file. A car has a mass of 1.4 tonnes. The distance between the front and rear wheel axles is 3.6m and the centre of mass is positioned 1.5m behind the front wheel centre and 0.8m above the road level. These details are attached in Figure Q1. The car, initially traveling at 12.6km/h, is accelerated up a stra

Circuit analysis and efficiency

A fully loaded 440V, three phase motor draws 12.4A at 86% power factor (pf). Its speed is 1730 rpm and its torque output to a mechanical load is 29.1 lb-ft*1.356=39.5Nm. What is the output HP and the efficiency?

Power Screws

A power square thread screw has a pitch diameter (dm) of 34mm, the lead of the screw 1 of 4mm, the frictional diameter of the collar (dc) of 40mm. The coefficients of friction are f=0.08 for the threads and fc=0.05 for the collar. the vertical load F per screw is 5 kN. How do I find the torque required to raise the load?

Solve: Computing the Torque

A force of 30N is applied perpendicularly to the face of a door at a distance of 1.5 m from the hinge of the door. Find the torque on the door about its hinge: a. 20 n/m b. 2nm c. 45Nm d. 20Nm

Stress Conditions, Etc.

A simple explanation of these solutions would be much appreciated. Could you also include any relevant comment along the way to help me understand your method and this subject better? Sketches are required. Can you also include Mohr's circle? Please find the questions in the attachment below. Hope you can help with this revis

Rotational Dynamics and Net Torque

A 10 kg solid disk of radius 0.50 m is rotated about an axis through its center. If the disk accelerates from rest to an angular speed of 3.0 rad/s while rotating 2.0 revolutions, what net torque is required?

Magnitude of Force Applied to a Wooden Board

A force is applied to the end of a 2ft long uniform board weighing 50lbs, in order to keep it horizontal, while it pushes against a wall at the left. If the angle the force makes with the board is 30 degrees, the magnitude of the applied force F is... a. 28.9lb b. 50lb c. 100lb d. 57.7 lb

Strength of Materials

1. A solid round steel shaft 3 1/2 inches in diameter transmits 100 HP at 200 RPM. Determine: a. Torsional stress in the outer fibers b. Angle of twist per foot of shaft c. Increase in stress at the outer fibers if the shaft is made hollow with a 1 1/2 inch bore. d. Stress at the inner fibers of the hollow shaft. e. Angle

Force Diagram, Tension and Torque Problem

A heavy pole, of mass M and length L, is freely hinged to a wall at the point O. A rope connects the other end of the pole, B, to a fixed point A on the wall above O. The system is in equilibrium, with the pole making an angle of θ with the horizontal, and the rope making an angle α with the horizontal... (i)Draw a for

Maximum Power Transmitted; Maximum Torsional Shear Stress

Leather belting 75mm wide is to be used to transmit power between two parallel shafts which run at the same speed. The pulleys are 0.6 m diameter. At slow speeds the tension in the slack side is half the tension in the driving side and the angle of lap on the pulley is 180 degrees. If the maximum load on the belting is not to ex

Winding Drum of Lift

In the figure (attached), the winding drum of a lift is driven by an electric motor via a gearbox having a reduction ratio of 20:1. The direct inertia on the motor shaft is 0.05 kg m2 and that on the winding shaft is 20 kg m2. The drum, which has a diameter of 600 mm, moves a lift by means of a cable wound around it. If the li