SPEED

speed (m/s) = distance (m) time (s)

Speed is the distance travelled in acertain time.

eg How fast did the cheetah run?

time = 5 sec

speed = dist = 20 = …… m/s. time 5

20m

SPEED

speed (m/s) = distance (m) time (s)

Speed is the distance travelled in acertain time.

eg How fast did the cheetah run?

time = 5 sec

speed = dist = 20 = …… m/s. time 5

20m

Calculate these speeds:

1. A plane flies 2000m in 10sec.

2. A car travels 1km in 50sec.

3. An explosion is heard 2 seconds after seeing a building crumble 660m away. What is the speed of sound?

4. The sun emits a solar flare. 8.4 Mins later a burst of X-rays is detected on earth. What is the speed of light? ( Distance from earth to sun is 150 million km)

DISTANCE TIME GRAPHS

distance (m)

ii 20

10 i. iii

0 5 10 15 20 25

time (sec)

i. run 20m into jungle speed = dist = ? = ? m/s time ?

ii. see a snake & stop for ……….. sec.

iii. walk backwards speed = dist = -20m = -1.3m/s time 15s

DISTANCE TIME GRAPHS

distance (m)

ii 20

10 i. iii

0 5 10 15 20 25

time (sec)

i. run 20m into jungle speed = dist = ? = ? m/s time ?

ii. see a snake & stop for ……….. sec.

iii. walk backwards speed = dist = -20m = -1.3m/s time 15s

DISTANCE TIME GRAPHS

distance (m)

ii 20

10 i. iii

0 5 10 15 20 25

time (sec)

i. run 20m into jungle speed = dist = ? = ? m/s time ?

ii. see a snake & stop for ……….. sec.

iii. walk backwards speed = dist = -20m = -1.3m/s time 15s

The slope tellsus the speed:

speed =

20m = 5m/s 4s

Distance Time graphs

Q1. What is the distance travelled in the first 5 sec?Q2. What is the speed during part A?Q3. How long did he stop for?Q4. What was his speed during part C?

Theo goes for a short bike ride….

Draw a distance:time chart for your journey to school