Expt1 - For Oral Report

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Experiment 1


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2005-12-31

Course NameMore Description About the Course

Your NameYour Title

1st Line ofYourOrganization2nd Line ofYour

Organization

Certain devices are used to obtain accurate

measurements of an object. During the course of

the experiment, three measuring devices wereused to accurately measure the dimensions of the

given object. Each measuring device can measure

from a scale of centimeter to millimeter

accurately up to two decimal places.

Summary of the Experiment


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Introduction

The instruments used are:

vernier caliper

micrometer caliper

foot rule

Each are used to obtain

precisely accurate

measurements.


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2005-12-31

Course NameMore Description About the Course

Your NameYour Title

1st Line ofYourOrganization2nd Line ofYour

Organization

Objectives

To study errors and how they propagate in a simple experiment

To determine the average deviation of a set of experimental

values obtained

To determine the mean of a set of experimental values as wellas set of average deviation of the mean

To familiarize the students with the vernier calliper, micrometer

calliper and foot rule

To compare the accuracy of the measuring devices used

To compare the accuracy of the measuring devices used

To Determine the density of an object given its mass and

dimensions.


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Theory

Average Deviation

Mean Deviation

Mean Diameter

Volume

Density

% Error Density

a.d.= d

n

A D =d

n

d= re ding me n di meter

V=4

3 r

3

D=m

V

%E o =D

EVD

AV

DAV

100


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Methodology

The experiment was conducted with the giveninstruments mainly the vernier caliper,

micrometer caliper and the foot rule.

T

he metal balls given to each group measuredits diameter.

The objective was to find out what measuring

device is more accurate by getting the % error

of each measurement.


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Vernier Caliper

1. Inside jaws

2. Retaineror locking screw3. Vernier scale (inch)

4. Rail (inch)

5. Depth probe

Front end of the rail

Main scale (mm)Vernier scale (mm)

Sliding Jaw

Outside jaws

Fixed Jaw


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Micrometer Caliper & Foot Rule


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Results & Discussion

Acitivity 1 Diameter of Sphere (cm)Trial Foot Rule Vernier Caliper Micrometer

Caliper

1 1.5 1.580 1.579

2 1.5 1.775 1.5763 1.5 1.570 1.575

4 1.5 1.550 1.580

5 1.5 1.770 1.574

6 1.5 1.565 1.5857 1.5 1.585 1.584

8 1.5 1.580 1.579

9 1.5 1.575 1.578

10 1.5 1.585 1.580


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Acitivity 1 Diameter of Sphere (cm)

Foot Rule Vernier Caliper Micrometer Caliper

Mean Diameter 1.5 1.574 1.579

(a. d.) 1.5 1.574 1.579

(A. D.) 0.474 0.498 0.499

Volume 1.767 cm 2.042 cm 2.061 cm

Mass 16.28 g 16.28 g 16.28 g

Experimental

Value of density

9.213 g/cm 7.973 g/cm 7.899 g/cm

Accepted Value of

Density

7.86 g/cm 7.86 g/cm 7.86 g/cm

% Error for Density 17.21 % 1.24% 0.50%


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Activity 2

Group

Member

1 2 3 4 5

Width of

Thumb (in)

0.64 0.82 0.60 0.62 0.66


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The possibilities of having a % error in the

experiment are the accuracy of the used

instruments. In the said data the foot rule isthe least accurate while the micrometer

caliper deems to be the more efficient tool

in measuring the metal ball.


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Conclusion

The group concluded that it is more efficient to

use measuring devices that can measure

objects up to 0.01mm.T

he reason is that theless % error we obtain the more we are near to

its true value.


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Applications

1) Which among the three measuring devicesgive you the least % error? Is the accuracy of a

measurement affected by the least count of the

measuring devices?

The group concluded that it is more efficient to

use measuring devices that can measure

objects up to 0.01mm. The reason is that theless % error we obtain the more we are near to

its true value.


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Applications

2) What do you mean by error? What are thetypes of error? What are the errors you

encountered in this experiment?

Error because the group was not able to perfectly

reach the accepted value of density. There was a

small margin of error. In measurement there are two

types of error. These are random and systematic

errors. The group were able to encounter random

errors. Some of the values increased and decreased

due to different approximations of each member.


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Applications

3) Sketch

a. a vernier caliper that reads 3.48 cm


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Applications

3) Sketch

b. a micrometer caliper that reads 7.05 mm


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Applications

4) A student weigh himself using a bathroomscale calibrated in kilograms. He reported his

weight in pounds. What is the percentage error

in his reported weight if he uses this

conversion: 1 kg = 2.2 pounds? The standard

kilogram is equal to 2.2046 pounds.

0.21 %


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Applications

5) In an experiment on determination of mass ofa sample, your group consisting of 5 students

obtained the following results: 14.34 g, 14.32 g,

14.33 g, 14.30 g and 14.23 g. Find the mean,

a.d. and A.D. Suppose that your group is

required to make only four determinations for

the mass of the sample. If you are the leader of

the group, which data will you omit?Recalculate the mean, a.d. and A.D. without

this data. Which results will you prefer?


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Applications

Answer #5

Set 1 (with 5 data)

mean=14.304g

a.d.=14.304 gA.D=6.40g

Set 2 (with 4 data)

14.23 g was omittedmean=14.3225g

a.d=14.3225g

A.D=7.16g

The group chose the 2nd set

of data with only 4

determinations for the massof the sample. The mass

omitted from the data is

poor in precision; therefore

it is not reliable as comparedto other data. Including the

omitted data will only

increase the % error.


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Applications

6) Give other parts of the body that are beingused for measurement even today. What are

some properties to be a standard of

measurement?

The use of the hand which is about three or

four inches. This measurement is still used to

reckon the height of horses. The thumb whichis probably the basis of the measurement now

called an inch.


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Prepared by: Group 1 III Bio 2

Jack Danielle Abuan

Jenn Marie Vannesa Alcalde

Pocholo Mari Arabit Chariz Shane Atienza

Aaron Agustine Aurelio

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