faculty of manufacturing engineering and technology management

8/7/2019 Faculty of Manufacturing Engineering and Technology Management

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FACULTY OF MANUFACTURING ENGINEERING AND TECHNOLOGY MANAGEMENT

BFM 2821

MECHANIC LABORATORY

LAB REPORT OF EXPERIMENT 03

(CENTRE OF GRAVITY)

GROUP MEMBERS :

SARINA BINTI SHAFIE (FB09066)

NUR QAMARINA ZAUDI (FB09043)

RADIAH ABD RAZAK (FB 10051)

MUHAMMAD IQBAL BIN JAAFAR(FB 09035)

AHMAD FATHI ZAINUDDIN (FB 09041)

SECTION : F 09/10

COURSE : MECHATRONICS ENGINEERING

LAB INSTRUCTOR: FAKROL ANUA BIN TALIB

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1. Title of the presentation

Report of Centre Of Gravity (LAB 03)

2. Theoritical Fundamental

The force of gravity is the force of attraction between all masses in the universe;

especially the attraction of the earth's on bodies on its surface. The body

experiences a downward pull when gravity acts on it. This force is equivalent to

a single downward pull force act on a body, which acts through the centre of

gravity. This is shown by the fact that a body can be supported by a single force,

which acts on the centre of gravity at the upward direction.

It is important to know the center of gravity in machine design.

In fact, the weight of the moving and rotating parts of a machine is concentrated

on the center of gravity. Hence the center of gravity of machine is often

considered when cutting the metal parts for making it component. The exact

location of center of gravity of a component is dependent on its shape, which is

addressed in this experiment.

The objective of this experiment is to determine the position of the centre of

gravity of various shaped plates.

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3. Experimental set-up

Apparatus

Apparatus Quantity/Specification Figure

Mounting panel 1 NIL

Rectangle plate 1

Circularplate 1

Triangle plate 1

T plate 1

Rhomboid plate 1

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Apparatus Quantity/Specification Figure

Irregular plate1

Knurled nut (P11) 1

Pivot screw (P1) 1

Plumb bob and line 1

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Figure 1 : Experiment Setup

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4. Experiments procedures

4.1 Prepa

rat

io

n1. The mounting panel was secured in the vertical position.

2. The support pin was inserted through one of the holes in the

upper half of the mounting panel.The pin was secured with nut.

3. The plate surface was ensured clean is clean.

4.2 Test 1

1. The plate was suspended with the support pin in one of the holes atthe outer side of the plate.

2. The plumb-line was hooked on the support pin in front of

the plate. The position was marked ofthe plumb-line on the

face of the plate with pencil dots (when the plate and plum-

line is at restposition).

3. The plate was removed and a line was drawn through the pencil dots.

4. The steps were repeated with the plate suspended from the two outerholes.

5. The lines intersected was drawn at one of the inner hole. This hole wasmarked with the letterG.

6. The test for all plates available were repeated .

4.3 Test 2

1. The plate was suspended with the support pin through each of the innerholes.

2. The plate was rotated and observed how it comes to rest.

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RESULTS

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6. Summary

Discussions

In Test 2 it can be observed that rotation of each plate is slower when

the position of holes is not at the center of gravity and vice versa.

Also. the r otation of each plate was influence d by the position of hole

and distance of holes from the canter of gravity.

The longer the distance of the outer holes from the center of gravity,

the more harder the plate to rotate and vice versa.

Conclusions

The position of the centre of gravity of various shaped plate was determined for

each shape mostly according to the ability of each of the plate to rotate easily on

the board. Different shape of plate have different ability to rotate and hence

have different centre of gravity.

The center of gravity makes the plate stable and balance and it is easy to rotate

the shape at the center of gravity holes without slipping.

The objective of this experiment is achieved.

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