# tutorial_5 - Mechanics tutorial_5 1 ans For a cylinder of...

This preview shows pages 1–3. Sign up to view the full content.

Mechanics tutorial_5.doc 1 1. For a cylinder of radius a, mass M, and length L, determine (a) the moment of inertia about the axis of the cylinder and (b) moment of inertia about an end diameter. ans: (a) Ma 2 /2 (b) M(a 2 /4 + L 2 /3) 2. The diagram shows a drum of cylinder radius r and flank radius R. If the cable is horizontal and the friction between the ground and the drum is sufficient to prevent slip, what is the acceleration of the drum given tension in cable is T. Discuss the direction of motion when the drum starts from rest. Mass of drum is M, moment of inertia about drum axis is I G . r R T cable ans: T(1-r/R) / (M + I G /R 2 ) 3. The diagram shows two pulleys, P 1 and P 2 , connected by a belt. The effective radius of P 2 is r and its axial moment inertia is I. The system is initially at rest and the tension in the belt is T o . The motor M which drives the pulley P 1 is then started and it may be assumed that the average tension T AB and T CD in sections AB and CD of the belt remains equal to T o . Denoting the anti-clockwise angular acceleration of pulley P 2 by and the clockwise resisting couple on the same axle by Q, find expressions for T AB and T CD , neglecting mass of the belt. A B P P 2 1 D C M ans: T o +(I +Q)/2r, T o +(I +Q)/2r

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Mechanics tutorial_5.doc 2 4. The diagram shows a hoist consists of a winding drum D driven by an electric motor M. A pinion of N M teeth on the motor shaft meshed with a gear wheel of N D teeth attached to the drum. The effective radius of the drum is R. The total axial moment of inertia on the drum shaft is ID and on the motor shaft is I M . The rope wrapped around the drum carries a load of mass m at its lower end which is being raised with an acceleration a. Neglect bearing friction and the mass and stretch of the rope; determine the couple being applied to the rotor of the motor. a M Drum D Pinion ans: Rmg R a mR N N I I N N C M D M D D M M 2 2 5. An experimental vehicle powered by a jet engine whose thrust can be represented by the
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 05/10/2009 for the course MXXM 2XX9 taught by Professor Gxxy during the Spring '09 term at City University of Hong Kong.

### Page1 / 6

tutorial_5 - Mechanics tutorial_5 1 ans For a cylinder of...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online