Travel graphs are a way to describe the movement of people or objects. They usually describe a trip that leaves and returns to a point (like a home base).
The vertical axis of a travel graph is the distance travelled from a starting point and the horizontal axis is the time taken from the starting point.
There are certain important features of a travel graph that we can use to interpret the journey being described:
Consider the following graph which displays a day long car tip with the horizontal axis being time in hours and the vertical axis being distance from home in kilometres:
(a) What speed did the car travel in the first hour? (Extended)
Think: We know that $$Speed=DistanceTime. How far did they travel in the first hour?
Do:
Speed | $$= | $$DistanceTime |
$$= | $$80 km1 h | |
$$= | $$80 km/h |
(b) What happened between the times of $$1 and $$2?
Think: What does it mean for the graph to be horizontal?
Do: The car was stationary for $$1 hour. Perhaps a break for lunch or a visit to a park.
(c) How far is the car from home after $$6 hours?
Think: Read the vertical axis for the distance at $$6 hours.
Do: The car is $$50 km from home.
(d) What was the average speed of the car over the $$6 hour journey? (Extended)
Think: How far has the car travelled in total? The car initially travelled $$80 km, then was stationary for one hour, then travelled a further $$120 km before starting the return tip home at $$4 hours into the journey. In the last section of the journey they are returning to home from $$200 kilometres away and reach $$50 kilometres from home, thus they travel $$150 km.
Do:
Total distance travelled | $$= | $$80+120+150 km |
$$= | $$350 km |
Average speed | $$= | $$Total distancetime |
$$= | $$350 km6 h | |
$$= | $$58.3 km/h |
Which graph shows the height of a ball being thrown vertically into the air?
Ben travels forwards and backwards along a straight line.
The graph shows Ben's distance from his starting point at various times of the day.
When did Ben start his journey?
How far did Ben travel by $$11 am?
What happened to Ben's speed at $$11 am?
Ben decreased his speed at $$11 am.
Ben did not change his speed at $$11 am.
Ben increased his speed at $$11 am.
Evaluate Ben's speed between $$11 am and $$1 pm.
What distance did Ben travel between $$1 pm and $$2 pm?
What is the furthest distance travelled from the starting point?
What is the total distance travelled by Ben from $$9 am to $$4 pm?