# Chapter 1 - Objectives and Summary

### for the OUP text Senior Physics - Concepts in Context by Walding, Rapkins and Rossiter

LEARNING OBJECTIVES
Knowledge & Understanding

• List the SI standard quantities together with their symbols, units and abbreviations.
• Distinguish between a basic quantity and a derived quantity.
• Convert from one unit to another.
• List and classify the possible sources of errors encountered when making a measurement.
• Find systematic and random errors. Calculate the error in an experiment.
• Convert from exponential to decimal and vice versa.
• Arrange a set of numbers in order of magnitude.
• Use significant figures in calculations.
• State simple error combination rules.

Scientific Techniques

• Read linear, vernier and micrometer scales.
• Estimate length, time, mass and number.
• Determine the error in the value of pi by experiment.
• Collect and analyse primary data by experiment.
• Locate and comprehend relevant information from secondary data sources.

### CHAPTER 1 SUMMARY

• Early measurements were based on body or heavenly features and differed from country to country.
• There is an international system of units called SI which is most commonly used around the world and by scientists.
• Measurable features or properties of objects are often called physical quantities. All physical quantities should be quoted with their numerical value and their unit.
• Fundamental quantities (or base quantities) are those which are used to define all other quantities (derived quantities).
• All measurements include errors or uncertainties, either systematic or random.
• Powers of 10 are called exponential notation. Scientific notation includes exponents in the form M x 10n, where M is a number having a single non-zero digit to the left of the decimal point and n is a positive or negative exponent.
• The order of magnitude is the power of 10 closest to to the number.
• Significant figures are those digits in a number that are known with certainty plus the first digit that is uncertain.
• Instruments used in measuring length include the ruler, the micrometer and the vernier calliper. Rotational speeds can be measured with a xenon stroboscope but there can be freezing' hazards.
• Digital measurements in the on/off form can be taken with simple counters or computer interfaces.
• Ideal measuring devices have no effect on the measurement itself.