# Chapter 2 - Objectives and Summary

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

LEARNING OBJECTIVES
Knowledge & Understanding

• Distinguish between and explain the meaning of the terms distance, displacement, speed, velocity and acceleration.
• Use these terms to describe the motion of objects.
• Distinguish between instantaneous and average velocity.
• Identify scalar and vector quantities and use appropriate sign conventions.
• Solve problems involving, velocity, acceleration, displacement and time.
• Use equations of motion to solve problems:
v = s/t; v = u + at; s = ½(u + v)t; s = ut + ½ at2; v2= u2 + 2as.
• Describe the motion of objects falling vertically under gravity (* including cases involving terminal velocity).
• Explain how the acceleration due to gravity can be determined.
• Discuss methods used to record motion.
• Solve problems involving combinations of displacement, time, velocity and acceleration.
• Apply equations of motion to the complex motion involved in domestic, industrial and scientific applications.
• Critically examine the adequacy of data presented in a variety of real-life situations.

Scientific Techniques

• Plot, interpret and use graphs to describe motion.
• Describe relationships between these graphs of motion.
• Tabulate and analyse motion from ticker–timer tapes.
• Use mathematical and vectorial operations to quantify, analyse and interpret data generated by ticker-timers, stroboscopes, electronic timers and computer interfaces.
• Use appropriate units of measurement correctly in calculations, reports and tables.
• Relate modern ideas to the historical development of the nature of motion.

### CHAPTER 2 SUMMARY

• The change of position in a particular direction is displacement.
• The average speed of an object is the distance covered divided by the time taken. The average velocity is the displacement divided by the time taken.
• Instantaneous velocity is the rate of change of displacement.
• The acceleration of an object is its change in velocity divided by the time taken for the change.
• The gradient of a displacement-time graph is the instantaneous velocity.
• The area under a velocity-time graph indicates the displacement.
• The gradient of a velocity-time graph indicates the acceleration.
• Objects that fall freely under gravity on Earth have a constant acceleration of about 10 m s-2 in the negative (downwards) direction.
• Stopping distance equals reaction time plus braking distance.