PHYSICAL QUANTITIES AND MEASUREMENTS

Objective

To obtain derived quantity from base quantities To ensure consistency, sensitivity and accuracy of instruments

Inference

1. Base quantities are the quantities that cannot be defined in terms of other quantities.

2. Derived quantities are physical quantities derived from the base quantities through multiplication, division or both.

3. Density of substance, ρ = mass = m Volume v

4. Relative density,

Hypothesis

1. Measuring physical quantity precisely.2. Differentiate between base and derived quantities.

Apparatus /Material

Wooden block, vernier calliper, beam balance, glass rod, ruler, metal block, measuring cylinder

Experiment 1a

Apparatus 1. Wooden block 2. Vernier calliper3. Beam balance/ Electronic balance

Procedure1. Measure the dimension of the wooden block by using vernier calliper.2. Weigh the mass of the wooden block by using Beam balance / Electronic

Balance.3. Record all the data in the TABLE 1.0

Result

Dimension Reading

Height, h 3.85 cm 3.85X10-2 mWidth, w 6.62 cm 6.62X10-2 mLength, l 10.21 cm 10.21X10-2 mMass, m 236.1 g kgVolume, V cm3 m3

Density, ρ g cm3

kg m3

Relative Density, ρr

Experiment 1b

Apparatus 1. Glass rod2. Micrometer screw gauge / vernier calliper3. Beam balance / electronic balance4. Ruler

Procedures1. Measure the dimension of the glass by using Micrometer Screw Gauge

or Vernier Calliper2. Record all the data in TABLE 2.0.

Result

Dimension ReadingDiameter, D cm mLength, l 16 cm 0.16 mMass, m 14.5 g mVolume, V cm3 m3

Density, ρ g cm3

kg m3

Relative Density, ρ r

Experiment 1c

Apparatus

1. Metal block / rod2. Micrometer screw gauge / vernier calliper3. Beam balance / electronic balance 4. Measuring cylinder 5. Scissor6. String

Procedures

1. Measure the dimension of the metal by using micrometer screw gauge or vernier callipe.

2. Record all the data in TABLE 3.0

Result

DimensionReading

AverageTrial 1 Trial 2

Diameter, D/ width, wLength, lMass, mExperiment Volume, Vexp

Theory volume, Vtheory

- using formulaExperiment density, ρ exp

Theory density, ρ theory

% error for densityRelative density, ρ r

Questions

State the precautionary steps to avoid errors in the experiment . Repeated reading are taken and the average value is calculated Avoid parallax error Avoid zero error Use instruments which is not defective

Conclusions

The derived quantities can be calculated or expressed in terms of base quantities

Exercising greater care and effort when taking readings

Experiment 1a

Experiment 1b

Experiment 1c