A yo-yo-shaped device mounted on a horizontal frictionless axis is used to lift a 19-kg box. The outer radius R of the device is 0.50 m, and the radius r of the hub is 0.20 m. When a constant horizontal force !@#$%^&p of magnitude 154 N is applied to a rope wrapped around the outside of the device, the box, which is suspended from a rope wrapped around the hub, has an upward acceleration of magnitude 0.80 m/s2 What is the rotational inertia of the device about its axis of rotation?
Do I first need to calculate Fg where Fg = m*g = (19)(9.8) = 186.2 N??? Then Fsum = !@#$%^&p + Fg = 154 + 186.2 = 340.2 N. I know that I can also find the tilt angle theta where theta = arctan (!@#$%^&p/Fg) = 39.59 degrees but I am not sure if I need that. What should I do next???

I am not certain of the picture. What I see is a rope on the inner hub pulling a weight.

force*innerradius= torque slowing down

Outer force*outer radius - lifting force*inner radius= I*angularacceleration

Now, be careful here: the lifting force is 19g + 19*acceleration, where acceleration is innerradius*angularacceleration

so solve for I, you know all else. I have no idea of a tilt angle entering here.

  1. 👍 0
  2. 👎 0
  3. 👁 124
asked by Calvin

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    a wheel radius 0.25 m is mounted on a frictionless horizontal axle. the moment of inertia of the wheel about the axis is 0.040. a light cord wrapped around the wheel supports the 0.50 kg of box. the wheel is released from the

    asked by sam on April 28, 2013
  2. Physics

    In the figure below, a wheel of radius 0.275 m is mounted on a frictionless horizontal axle. A massless cord is wrapped around the wheel and attached to a 1.95 kg box that slides on a frictionless surface inclined at angle θ =

    asked by Kimberley on April 3, 2016
  3. College Physics

    A wheel of radius 0.398 m is mounted on a frictionless horizontal axis. The rotational inertia of the wheel about the axis is 0.0576 kg·m2. A massless cord wrapped around the wheel is attached to a 0.790 kg block that slides on a

    asked by Stephanie on July 6, 2012
  4. Physics

    A device consists of eight balls each of mass 0.4 kg attached to the ends of low-mass spokes of length 1.8 m, so the radius of rotation of the balls is 0.9 m. The device is mounted in the vertical plane. The axle is held up by

    asked by Emily on April 14, 2013
  5. physics

    Two boxes (b1 = 23 kg and b2 = 57 kg) are being pushed across a horizontal frictionless surface, as the drawing shows. The 48-N pushing force is horizontal and is applied to the 23-kg box, which in turn pushes against the 57-kg

    asked by cody on February 10, 2012
  6. Physics

    A 4.5kg box slides down a 4.1-m -high frictionless hill, starting from rest, across a 1.7-m -wide horizontal surface, then hits a horizontal spring with spring constant 490N/m . The other end of the spring is anchored against a

    asked by Lena on June 8, 2014

    A 100 kg box on the right and a 50 kg box on the lift are tied together by a horizontal cable. The 100 kg box is acted upon by an external force of 500 N to the right. The fritional force exerted by the floor on the 100 kg box is

    asked by LESTER on October 3, 2016

    Two horizontal forces, F1 and F2, are acting on a box, but only F1 is shown in the drawing. F2 can point either to the right or to the left. The box moves only along the x axis. There is no friction between the box and the

    asked by Tiffany on February 2, 2011
  9. Physical Science

    an initially stationary 15.0 kg crate of cheese wheels is pulled via a cable a distance d = 5.70 m up a frictionless ramp to a height of h = 2.5 m, where it stops. What is its potential energy of the crate after it is lifted? how

    asked by junior on June 24, 2011
  10. Physics

    Boxes A and B are in contact on a horizontal, frictionless surface. Box A has mass 21.0 kg and box B has mass 8.0 kg . A horizontal force of 100N is exerted on box A. What is the magnitude of the force that box A exerts on box B?

    asked by Sarah on June 15, 2015

More Similar Questions