This document outlines an assignment for determining the mass moment of inertia of a flywheel. It provides the theoretical equation for mass moment of inertia as 1/2Mr^2, where M is the mass of the flywheel and r is the radius. The procedure involves rotating the flywheel to lift a weight and recording the time and revolutions taken for the weight to fall. Multiple trials are conducted to calculate the experimental mass moment of inertia. Students are instructed to prepare a report of their assignment results, including sketches and observations tables.

1. AM 108: Engineering Mechanics
Practical

2. Syllabus
• Plane Force Polygon
• Forces in Space
• Simple Plane Roof Truss
• Coplanar Parallel Forces
• Modulus of Elasticity by Searle’s Apparatus
• Belt Friction
• Static Surface Friction
• Gravitational Acceleration
• Mass M.I. of Flywheel

3. Assignment 9
• Mass M.I. of Flywheel
– Aim
• To determine mass moment of inertia of a flywheel

4. Assignment 9
• Mass M.I. of Flywheel
– Flywheel
• Massive wheel having its mass concentrated at the
periphery
• Has large radius
– Large mass moment of inertia
» Useful to store kinetic energy
effectively
• Theoretical mass moment of inertia
½ Mr2
M = Mass of flywheel in kg
r = Radius of flywheel in m

5. Assignment 9
• Mass M.I. of Flywheel
– Theoretical mass moment of inertia
½ Mr2
M = Mass of flywheel in kg
r = Radius of flywheel in m

6. Assignment 9
• Mass M.I. of Flywheel
– Experimental mass moment of inertia
• N = Total number of revolution made
by flywheel
– From start to till it stops automatically
• n1
= Number of revolution made by
flywheel till effort pan touches
ground

7. Assignment 9
• Mass M.I. of Flywheel
– Procedure
• Measure the diameter of load drum (flywheel) and axle
• Attach one end of the cord to hook on axle and rotate
flywheel so as to bring weight at the other end of rope
to desired starting position
– Take care that coils of cord make a closed loop
• Measure height of load from ground (h)
• Repeat weight and record time of pan to touch ground
by stop watch
– At the same time count number of revolutions till pan touches
ground. Also count total number of revolution made by flywheel
until it comes to rest

8. Assignment 9
• Mass M.I. of Flywheel
– Observations Table
M = Mass of flywheel = 23.75 kg
d = dia. of axle = 0.0366 m
d1 = dia. of chord = 0.0079 m
R = Radius of axle = 0.0183 m
r = Radius of flywheel = 0.18 m
Theoretical mass M.I. = ½ Mr2
= __________
(kg.m2)
Experimental mass = _______ kg.m2
(Average)

9. Assignment 9
• Mass M.I. of Flywheel
– Observations Table
S.No.
Weight
of pan +
wt. in the
pan W
(kg)
Height
of pan
from
ground
h (m)
Total
number of
revolution
made by
flywheel N
No. of
revolution
till pan
touches
ground n1
Also, n1
=
Time for pan
touch the
ground t
(second)
M.I.
(kg.m2
)
1 0.28 0.9 21 6.5 37.31
2 0.33 0.9 28 6.5 28.21
3 0.38 0.9 30.5 6.5 24.90
4 0.43 0.9 34.5 6.5 23.90
5 0.48 0.9 38.75 6.5 21.98
6 Unknown
P
0.9 23.75 6.5 31.09

10. Assignment 9
• Mass M.I. of Flywheel
– One virtual video
• https://www.youtube.com/watch?v=e-f5M_7__so
• https://www.youtube.com/watch?v=9MBE5t1Sv_w
• https://www.youtube.com/watch?v=n4Vw8H5T2CI

11. Assignment 9
• Report Preparation
– Specify Name, Roll No. and Date in Title Page
– Signature at each page of assignment
• At bottom left corner
– Sketch drawings in A4 sheets
• Specify Name, Roll No., Date and Signature at bottom
right corner
– Scan the drawing and place it in appropriate location of
Assignment
– Make a PDF Document of Report
• Name the PDF Document with your Roll No.
– Submit within two weeks

12. Thank you!