Measurement

Introduction. The purpose of this activity is to acquaint you with the basic tools and methods of scientific measurement that you will be expected to master if you wish to participate fully and meaningfully in the laboratory setting. Demonstrable skill with the tools of measurement and sufficient competence in the methods by which meaningful measurements are obtained are the cornerstones of all scientific investigation.

Data.

Measurement of Linear Features.

Measure the following with a meter stick to the nearest 0.1 centimeters and record on the

lines provided. Convert your values to meters and record on the lines provided.

Equipment. [Photographs to Follow]

Meter stick

Hooked Masses: 200g, 500g, and 1000g

Aluminum cylinder

Rectangular cut polystyrene sponge

Stopwatch

Physical Setting: Physics Reference Tables Triple beam balance

Protractor

Spring Scale

Length of the Classroom Door ____________________ cm ________________________ m

Width of the Classroom Door _____________________ cm ________________________ m

Thickness of the Classroom Door _________________ cm ________________________ m

Length of the Front Blackboard ___________________ cm ________________________ m

Width of the Front Blackboard ____________________ cm ________________________ m

Length of the Meter Stick _______________________ cm ________________________ m

Width of the Meter Stick ________________________ cm ________________________ m

Thickness of the Meter Stick _____________________ cm ________________________ m

Length of Polystyrene Sponge ____________________ cm ________________________ m

Width of Polystyrene Sponge _____________________ cm ________________________ m

Thickness of Polystyrene Sponge _________________ cm ________________________ m

Radius of Aluminum Cylinder ______________________ cm ________________________ m

Height of Aluminum Cylinder ______________________ cm ________________________ m

Measurement of Mass.

Measure the mass of the following with a triple beam balance to the nearest 0.1 grams and record on the lines provided. Convert your values to kilograms and record on the lines provided.

Mass of Aluminum Cylinder ________________________ g ________________________ kg

Mass of Meter Stick _____________________________ g ________________________ kg

Mass of Polystyrene Sponge ______________________ g ________________________ kg

Mass of Protractor ______________________________ g ________________________ kg

Mass of Stopwatch ______________________________ g ________________________ kg

Mass of Reference Tables _________________________ g ________________________ kg

Determination of Surface Area.

Calculate the surface area of the following to the nearest cmexp2 and record on the lines provided. Convert your values to mexp2 and record on the lines provided in significant figures.

Measurement of Time.

Measure the time required for a 40-cm-long pendulum to complete ten cycles with the stopwatch provided and record to the nearest 0.01 second on the line provided. Repeat four additional times, record, and then average all trials. Calculate the time of a single cycle and record where indicated.

First Set of Ten Cycles ____________________________ s

Second Set of Ten Cycles __________________________ s

Third Set of Ten Cycles ____________________________ s

Fourth Set of Ten Cycles ___________________________ s

Fifth Set of Ten Cycles ____________________________ s

Average Time of All Five Ten-Cycle Sets _____________ s

Average Time of One Cycle _________________________ s

Determination of Volume.

Calculate/measure the volume of the following objects to the nearest cmexp3 and record on the lines provided. Convert your values to mexp3 and record on the lines provided in

significant figures.

Classroom Door ___________________________ cmexp3 _______________________ mexp3

Meter Stick ______________________________ cmexp3 _______________________ mexp3

Aluminum Cylinder _________________________ cmexp3 _______________________ mexp3

Questions.

Answer the following questions, thoroughly, thoughtfully, comprehensively, and intelligibly. Written responses must be in the form of complete, grammatically correct sentences. Mathematical responses must show all work, including equations and substitutions.

Briefly explain the meaning of the word precision as employed in the context of the Physics laboratory. Upon what is the precision of a measurement based? Relate the precision of obtained measurements possible with each of your tools of measurement, that is, the meter stick, triple beam balance, stopwatch, and protractor, respectively.

Briefly explain the meaning of the word accuracy as employed in the context of the Physics laboratory. Summarize the principal differences between absolute error and percent error and the methods by which each is obtained.

The density of a body is the ratio of its mass to its volume. Based on your recorded data, calculate the density of your meter stick (in grams per cubic centimeter), being mindful to express your answer in the appropriate significant digits. Show all work.

Based on your data as well as your answer to question 3, calculate the mass of the front door (in kilograms), assuming that the meter stick and the door are each comprised of the same type of wood and therefore possess equal density. Consult your conversion sheet if necessary.

Equations.

Area of Rectangle = Length x Width

Area of Triangle = 1/2 x Base x Height

Surface Area of Rectangular Solid = 2(Length x Width) + 2(Width x Thickness) + 2(Length x Thickness)

Volume of Rectangular Solid = Length x Width x Thickness

Volume of Right Cylinder = p x Radiusexp2 x Height (p = 3.14)

Based on your data as well as your measurement of the weights of the three individual hooked masses, write an algorithm (equation) which permits the direct conversion of the magnitude of a body's mass (in kilograms) to the magnitude of its weight (in Newtons). Think!