1. M

    Work Done by a Torque

    A flywheel of mass 182 kg has an effective radius of 0.62m (assume the mass is concentrated along a circumference located at the effective radius of the flywheel). a) What torque is required to bring this wheel from rest to a speed of 120 rpm in a time interval of 30.0 s? b) How much work is...
  2. T

    Torque on a wire

    A wire is formed into a circle having a diameter of 10.0 cm and placed in a uniform magnetic field of 3.00 mT. The wire carries a current of 5.00 A. Find (a) the maximum torque on the wire (b) the range of potential energies of the wire field system for different orientations of the circle. For...
  3. A

    Torque due to friction

    Hi there, been given a problem and not quite sure where to start. A wheel starts from rest and rotates through 150 radians per second in 5 seconds. The net torque due to the friction and motor is constant at 48 Nm. When the motor is switched off, the wheel stops in 12 seconds. what is the...
  4. M

    Work done by a torque....

    How much work is done by the motor in a cd player to make a cd spin, starting from rest? The cd has a diameter of 12 cm and mass of 16.5 g. The laser scans at a constant tangential velocity of 1.13 m/s. Assume that the music is first detected at a radius of 21 mm from the center of the disk...
  5. M


    Problem: "A ferris wheel rotates because a motor exerts a torque on the wheel. The radius of the wheel is 67.5 m and its mass is 1.9 x 10^6 kg. The cruising speed of the wheel is 3.39 x 10^-3 rad/s. How much work does the motor need to do to bring the stationary wheel up to cruising speed?"...
  6. O

    net torque and acceleration

    70 cm diameter cylindrical disk has a mass of 10 kg and accelerates uniformly from 150 rpm to 300 rpm in 4 sec. a) find angular accleration. b) what are th radial and tangential components of linear accleration for a point on the edge of the wheel. C) what is th net torque acting on the wheel...
  7. A

    Torque on merry-go-round

    Hey guys, I don't seem to be able to get the right answer for this question eventhough I really thought I was going about it in the right way, here it is: They answer they got was 0.140 N and I got -0.02 N. :(
  8. C

    Force And Torque

    I'm trying to work out the torque required to move a linear table, driven by a 24v dc motor. The linear table will be moving a distance of 270mm which will have a weight of 8kg and moving over a period of 20s. This is a satellite system i'm designing which will have an antenna of 0.168m2 which...
  9. P

    Need rotational and translational equilibrium equations...

    Physics 6 - california In a lab experiment titled, Torque and Rotational Equilibrium, one of the questions asked is, "predict what the tension in the lower and upper spring balances will be using the equations of rotational and translational equilibrium." Can anyone tell me what are these two...
  10. S

    Torque Problem

    Two pier posts (P1 and P2) support a bridge that is 9 m long and has a mass of 80 kg. A boy with mass of 30 kg. is standing 3 m from the left end. Find the force exerted by P1 and P2. Appreciate some help.
  11. D

    Central forces and torque

    In rotational dynamics, it is said that central fores exert no torque on a system and therefore conserve angular momentum L . i.e. L = constant. This is because the force vector is directed along the radius vector. i.e. F parallel to r. However there seems to be a contradiction. If the...
  12. A


    Please help with problem Calculate the force exerted by each pier, F1 and F2, of a 5.0 m footbridge with a mass of 100 kg, evenly distributed, when a 55 kg person stands 2.0 m from one end of the bridge. Thanks from (Kiss) angelica
  13. C

    Torque, angular momentum and Gyroscopes.

    Hi, I have recently started revising for my mechanics exam and just can't seem to grasp the concept of Gyroscopes angular momentum and torque. I was wondering if anyone could please clarify the following things for me: 1. According to my textbook toque is the tendancy of a force to twist or...
  14. S

    Torque about the wheel's central axis

    A frictional force of 350 N acts on the rim of a 1.7 m diameter wheel to oppose its rotational motion. What is the torque about the wheel's central axis? (Take positive torques to be in the direction of rotation.) Ok ive tried taking 350N*.85 m but i use and it keeps saying i...
  15. C

    Finding Net Torque

    A bicyclist of mass 65.0 kg stands on the pedal of a bicycle. The crank, which is 0.170 m long makes a 45 degree angle with the vertical. The crank is attached to the chain wheel which has a radius of 9.70 cm . What force must the chain exert to keep the wheel from turning? (Bow)Thanks
  16. S


    i missed the lesson and test tomorrow!! argh!!! What is torque? What do you use it for? just explain whatever you can about. Thanks (Smile)
  17. B

    Equilibrium - Torque question

    1. The problem statement, all variables and given/known data A uniform 0.122 kg rod of 0.90 m length is used to suspend two masses as shown. At what distance x should the 0.20 kg mass be placed to achieve static equilibrium? 2. The attempt at a solution F1=1.96N F2=4.9N torque = 4.9 x...
  18. A


    A grindstone in the shape of a solid disk with diameter 0.540 m and a mass of m = 50.0 kg is rotating at = 880 . You press an ax against the rim with a normal force of = 260 N, and the grindstone comes to rest in 7.30 s. Find the coefficient of friction between the ax and the grindstone. You...
  19. J


    Hi guys...!!I'm stuck up with a torque calculation..Pls help me out. We have 2 wheels which rotates in opposite direction.A ball is fed in between the wheels.The ball gets squeezed a bit and is pushed out with a velocity of 180km/hr.To achieve this speed of ball what has to be the rpm of...
  20. J

    Torque ques.(pls advise...)

    Pls refer the attachment .... In the following illustration, it shows a rectangular, 20 turn loop of wire that is 12 cm by 5.0 cm. It carries a current of 0.10 A and is hinged on one side. It is mounted with its plane at an angle of 33o to the direction of a uniform magnetic field of 0.50 T...