Lesson 5— 4.3 distance time graphs

• Natuurkunde / Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 2

4.3 — Learning goals

·      Be able to read a distance-time graph.

·      Explain what information the gradient of a line in a distance-time graph gives you.

·      Be able to draw a distance-time graph based on the information in a table or a description of an objects motion.

·      Calculate the (average) speed of an object using a distance-time graph.   

Distance time graph

Shows how an object is moving 

Slope (gradient) of a line 

The slope is a measure of the steepness of a line.

Shows:

• The distance traveled

• How much time this took

•  How this distance was traveled

What you have to be able to do with it:

• Find the speed of a movement 

•  describe the trajectory of a movement

• determine wether an object is standing still, moving at a constante velocity or accelerating/ decelerating

• Distance travled?
  

• Time taken?
  

• Average speed
  

• Speed at each segment?
  

• Distance travled?
  

8 m

• Time taken?
  

10 s

• Average speed
  

v=d/t v=8/10= 0.8 m/s

• Speed at each segment? 1.25 m/s, 0 m/s,1m/s
  

Which of the two is faster?

•  The gradient of the slope shows the speed of a movement
•  blue is faster

A

B

What happens in segments 

A & B?

A

B

What happens in segments 

A & B?

A: steady speed going back where you started

B: not moving speed=0

What does a curved line indicate?

What does a curved line indicate?

What does a curved line indicate?

A- stationary B- constant speed (steady speed)

C- constant speed returning to start

D- acceleration(speeding up) E- deceleration (slowing down) 

F- constant speed

Slope=0

Slope +,                      Slope   _ , constant

constant

Exercise

John goes for a walk, he leaves at his house.

a) Calculate his speed for each segment. Also calculate his average speed.

b) How much distance did he travel in total?

c) Where does John end up?

at the end of his walK?

a) Calculate his speed for each segment. Also calculate his average speed.

AB: v=d/t 3/5= 0,6 km/h

BC= v=d/t 0/3=0 km/h

CD: v= d/t = 9/4= 2,25 km/h

DE v=d/t 0/2= 0 km/h

EF:  v= d/t  12:6 = 2 km/h

Average speed for the whole traject:

d= 3+0+9+0+12 = 24

Total time 20 h

V= 24 /20 = 1,2 km/h

Homework

• The worksheet of 4.3
  
• The workbook exercises of 4.3
  

4.3 — Learning goals

• Calculate speed using a distance-time graph

• Read a distance-time graph correctly