DO NOW

Q1. Which car is moving at constant speed?Q2. Which car is not moving? WHY?Q3. Which car is accelerating? WHY?

DO NOW

Q1. Which car is moving at constant speed? B (straight line)Q2. Which car is not moving? WHY? a (distance does not change over time)Q3. Which car is accelerating? WHY? Curved line

Today’s SLO’S

1. Define acceleration2. Interpret speed versus time graphs for

movement3. Plot distance and speed versus time graph

Read NMS2 pg 30-31

Answer all the questions + stretch yourself

NMS2 pg 30-31 (Answers)Acceleration P.30/31

1. The change in speed (m or Km) over time (sec or h).

2. N/A3. (a) constant speed (b) constant

(uniform) acceleration4. See next slide

Rachel and Stephen are moving with a constant speed since the slope of the line is constant.

Rachel – 5 ms-1; Stephen – 3 ms-1;

Kepa is accelerating. The slope is increasing so her speed is increasing.

Distance travelled for 3 cyclists

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10 11

Time (s)

Dis

tan

ce

(m

)

Rachel

Stephen

Kepa

Speeed vs time for 3 cyclists

0

2

4

6

8

10

12

0 1 2 3 4 5 6 7 8 9 10

Time (s)

Sp

ee

d (

ms

-1)

Rachel

Stephen

Kepa

Rachel – Constant speed of 7 ms-1 for 3 s then a constant deceleration to rest in a further 7 s.

Stephen – Constant acceleration from rest to 10 ms-1 in 10 s.

Kepa – Constant acceleration from rest to 10 ms-1 in 5 s followed by a constant deceleration to rest in a further 5 s.

• Video:http://www.youtube.com/watch?v=eSJ-HzNWJGM

HOMEWORK:• Pg 26-27 Workbook (WB)• Due Fri 7/05/10