Mapping Space and Mapping Space and TimeTimeTopic – Physics on the RoadTopic – Physics on the Road

Lesson 1Lesson 1

LEARNING INTENTIONS…LEARNING INTENTIONS…

Know that speed is distance divided by Know that speed is distance divided by time; v = s/ttime; v = s/t

That speed can be calculated from a That speed can be calculated from a distance-time graph.distance-time graph.

The meaning of average and The meaning of average and instantaneous speed and how these are instantaneous speed and how these are calculated from distance - time graphs.calculated from distance - time graphs.

TransportTransport

Geneticist Steve JonesGeneticist Steve Jones

“…“…there is little doubt that the most there is little doubt that the most important event in recent human history important event in recent human history was the invention of the bicycle”was the invention of the bicycle”

QuantityQuantity symbolsymbol unitsunits

velocity (or velocity (or speed)speed)

vv metres per secondmetres per second

m/s m/s oror ms ms-1-1

displacement displacement (or distance)(or distance)

ss metresmetres

mm

timetime tt secondsseconds

ss

accelerationacceleration aa metres per second per metres per second per secondsecond

m/s/s m/s/s oror ms ms-2-2

Distance – time dataDistance – time data

Time /sTime /s Distance / mDistance / m

00 00

1010 100100

1616 200200

2828 500500

4040 800800

6060 10001000

QuestionsQuestions

1.1. Mark acceleration, deceleration and Mark acceleration, deceleration and constant speed.constant speed.

2.2. What is the average speed of this What is the average speed of this journey?journey?

3.3. What is the highest instantaneous What is the highest instantaneous speed?speed?

GradientGradient

Explain the importance of Explain the importance of understanding gradient in interpreting understanding gradient in interpreting distance time data. In terms of distance time data. In terms of

1.1. identifying changes of velocityidentifying changes of velocity

2.2. calculating instantaneous speedcalculating instantaneous speed

1.1.You are watching a batsman hit a cricket ball. You are watching a batsman hit a cricket ball. If 0.375 s passes between the time you see If 0.375 s passes between the time you see him strike the ball and the time you hear the him strike the ball and the time you hear the sound of this, how far from the batsman are sound of this, how far from the batsman are you sitting? The speed of sound in air is 340 you sitting? The speed of sound in air is 340 msms–1–1. .

2.2. A girl diving from a 15 m platform wishes to A girl diving from a 15 m platform wishes to know how fast she enters the water. She is in know how fast she enters the water. She is in the air for 1.75 s and dives from rest (with an the air for 1.75 s and dives from rest (with an initial speed of zero). What can you tell her initial speed of zero). What can you tell her about her entry speed?about her entry speed?

3. An experiment performed on the Moon 3. An experiment performed on the Moon finds that a feather falls 20.75 m from rest finds that a feather falls 20.75 m from rest in 5 s. What is its speed as it hits the in 5 s. What is its speed as it hits the Moon's surface?Moon's surface?

4.4.Sketch a graph to represents the variation Sketch a graph to represents the variation in vertical height with time for a ball thrown in vertical height with time for a ball thrown upwards and returning to the thrower.upwards and returning to the thrower.

From this graph sketch a velocity–time From this graph sketch a velocity–time graph.graph.