Mon: 15°C, Tue: 10°C, Wed: 10°C
Real life graphs — Notes & Worked Examples Show / Hide
Explanation:
On a distance–time graph, a sloping straight line represents constant speed, a horizontal flat line means the object is stationary (stopped), and the gradient equals the speed (DistanceTime). Always check the time scale on the horizontal axis (e.g. 15 mins = 0.25 hours).
On a cost or conversion graph (such as taxi fares or utility bills), the y-intercept is the fixed standing charge, and the gradient (Change in yChange in x) is the rate per unit (e.g. cost per mile).
Example 1: A cyclist leaves at 09:00, travels 18 km by 09:45, rests 15 mins, then cycles 18 km home by 10:30. Find Stage 1 speed in km/h.
Example 2: A plumber's graph goes from (0, 45) through (3, 135) for hours x and cost y (£). Find the call-out fee and hourly rate.
Mon: 15°C, Tue: 10°C, Wed: 10°C
Worked Solution & Answer
The travel graph shows information about the train’s journey.
Give your answer in miles per hour. [2 marks]
Worked Solution & Answer
Distance = 35 miles, Time = 30 minutes = 0.5 hours M1
Speed = 35 ÷ 0.5 = 70 mph A1
Draw horizontal line at distance 35 from t = 30 to t = 45 B1
She runs for 3 hours.
Here is a distance-time graph of her run.
She then gets a bus home.
She arrives home at 11.30
Complete the distance-time graph.
Assume the bus travels at a constant speed. [2 marks]
Worked Solution & Answer
Resting for 1 hour: draw a horizontal line at 20 km from 09.00 to 10.00 M1
Bus travels home: draw a straight line from (10.00, 20) to (11.30, 0). A1
Worked Solution & Answer
⇒ 80 oz = 4 × 568 ≈ 2270 g A1
Worked Solution & Answer
2 × 6.25 = 12.5 stones A1
The travel graph of Amy’s walk to the skate park is shown below.
Worked Solution & Answer
He stayed at his friend's house and then drove home.
Here is Steve's travel graph.
Worked Solution & Answer
State the units of your answer. [2 marks]
Worked Solution & Answer
From 1.30 pm to 2.00 pm: 30 minutes
From 2.15 pm to 2.30 pm: 15 minutes
Total time = 30 + 15 = 45 minutes (or 34 hour) A1
From 2.00 pm to 2.15 pm: travels 29 - 25 = 4 miles
From 2.30 pm to 3.00 pm: travels 25 miles
Total distance = 29 + 4 + 25 = 58 miles A1
Here is part of a distance-time graph of her trip to the supermarket.
How far is the supermarket from her home? [1 mark]
How long does she stay at the supermarket? [1 mark]
It takes her 3 minutes longer than her journey to the supermarket.
Complete the distance-time graph. [2 marks]
Worked Solution & Answer
Outbound journey took 20 minutes (10.00 to 10.20) M1
Return journey takes 20 + 3 = 23 minutes
Leaves at 10.35, arrives home at 10.35 + 23 minutes = 10.58
Draw a straight line from (10.35, 7) down to (10.58, 0). A1