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## #1 Re: Help Me ! » Calculating Angular Acceleration. Im struggling a bit. » 2006-01-14 05:28:31

I am, im working on them now..., thats why I said I will be posting answers soon.

## #2 Help Me ! » Moment of Inertia, Potential energy, Velocity Problems (2) » 2006-01-14 05:18:58

woca
Replies: 1

Problem 1

Example A flywheel consists of a uniform steel disc of mass 20 kg and diameter
0.4m. It is lifted vertically 200m, and placed on an incline. The flywheel is then
released and rolls down the incline without slipping.

Find:
(a) the moment of inertia of the flywheel;
(b) the potential energy;
(c) the maximum linear velocity of the disc as it reaches the bottom of the incline;
(d) the maximum angular velocity.

Problem 2

A flywheel, of mass 500 kg, takes the form of a uniform disc of
diameter 1.5 m. The flywheel is fastened to a horizontal shaft lying in
bearings and is coupled to an electric motor.

Find:
(a) the moment of inertia of the flywheel assuming the contribution of the shaft is
negligible;
(b) the torque at the motor to give the flywheel/shaft system an acceleration of 6
(c) the power transmitted by the motor when a speed of 500 rev/min has been
attained;
(d) the height a mass of 2000 kg will be raised before the flywheel comes to rest. The
mass is fastened to a rope which is wrapped around a drum, which, in turn, is keyed to
the flywheel shaft. When the flywheel reaches a speed of 650 rev /min the motor is
disconnected and the flywheel/drum system is allowed to rotate freely.

Post workings out and answers here. I will also give them ago:)

## #3 Help Me ! » Calculating Angular Acceleration. Im struggling a bit. » 2006-01-14 05:14:43

woca
Replies: 3

Hi all,

Some questions,

1) The speed of an electric motor rises from 1430 to 1490 rev/min in 0.5 seconds.

Find the average angualr acceleration and the number of revolutions turned through this time.

2)The speed of a shaft increases from 300 to 360 rev/min while turning through 18 complete revolutions.

Calculate the angular acceleration and the time taken for this change.

Goodluck to all those who try. Please post any answers with working. Hopefully I will also be posting some answers soon.:)

## #4 Introductions » Hello All » 2006-01-14 05:06:54

woca
Replies: 2

Hi,

Im a university student and am studying Computer Aided Product Design. That isnt maths I here you ask?!

Well, one particular unit is.. and because I have never studied math at a level higher than GCSE I thought I would join this forum for a little help, and at the same time, swot up.

I will be posting some questions for people to have ago at, and maybe these people who understand the can help me to understand how to do them properly.

Thats it.

Bye