2. Each square horizontally represents half an hour. The convention on distance-time graphs is that the horizontal axis represents time and the vertical axis represents distance travelled (from the starting point). Here the axis is labelled with time of day, but exam questions often use time since the start of the journey. This distinction could be pointed out here. Units could also be discussed.

3. Brussels is 375km from Waterloo. Katie's vertical axis is labelled from 0 to 400km, marking 50km for every 2 squares. This section of the programme demonstrates appropriate choice of scales and ranges of values. Katie shows 115km and 165km on the graph. The horizontal axis uses a scale of 3 squares for each half-hour, or 10 minutes per square.

4. The tunnel is 50km long. The journey through it takes 20 minutes. Pupils could discuss Katie's conclusion that this gave a speed of 150 km/h.

5. This section of the graph was horizontal. Ben's final graph contains three horizontal sections, which represent 'rests' at the primary school, lunch and Top of the Pops.

6. The equation

(speed) = (distance) ÷ (time)

is used to calculate the speed of the train in France and Belgium. This can be related directly to the gradient of the graph, as shown by the triangle. The conversion from kilometres per minute to kilometres per hour could be discussed here. The calculation shown was 210km ÷ 80mins = 157.5 km/h. Are there alternative ways of arriving at this result?

7. Atomic Kitten spend 7 hours recording for Top of the Pops.

8. A return journey has a negative gradient. How do students perceive the difference between lines with negative and positive gradients? The group took an hour to return to the hotel, compared with 1¹/₂ hours earlier in the day to reach the school, which was nearer. Can students suggest why the return journey at 7pm is quicker?

9. Each hour is divided into 10 units, representing 6 minutes each. The example in the programme was chosen to reflect the common practice of working with standard graph paper, where a scale of 2cm:1h often leads to miscalculation based on the same assumption that Ben made.

10. The top speed is 300 km/h. Pupils should be able to calculate the time taken for the return journey and the arrival time at Waterloo given that the distance is 375km and the train sets off at 2pm.

Worksheet 2: Tick or Trash

Question 1

Student B is correct. Student A has wrongly converted 10 minutes to a decimal fraction of an hour. The correct decimal equivalent is 10/60 = 0.166....

Question 2

Student A is correct. Student B fails to show Mrs Hall's one-hour meeting correctly and completes the graph with the return journey starting at 3pm (but B does use the correct gradient).

Worksheet 3: Exam Practise Questions (Edexcel)

This is a selection of past exam questions from Edexcel, targeted at the middle ability range. You can use the sequence as it stands or select individual questions to suit your needs.

Given below is the mark scheme for each question, which will help you to see how marks are allocated and what the examiner is especially looking out for. The mark schemes use the following abbreviations:
oe
or equivalent
cao
correct answer only
ft
follow-through marks
dep
dependent
indep
independent
M
method marks
A
accuracy marks
B
benefit-of-doubt mark
SC
special case

Question 1

(a) i) 5km

ii) 11.20

iii) 10 minutes

(b) line (12.30,18) to (1.30,18); line (1.30,18) to (3,0)

Notes:

(a) B1. B1. B1.

(b) M1 for lines (12.30,18) to (k,18) and (k,18) to (3,0). A1 cao if k = 1.30. (If only line (1.30,18) to (3,0) drawn give M1, A1.) SC: If only line (12.30,18) to (1.30,18) drawn give B1.

Question 2

(a) 88m

(b) AB constant speed. BC gradually slowing down. CD stationary.

Question 3

(a) 2

(b) Graph completed.

Notes:

(a) B1 cao.

(b) B1 horiz. line (2,30) to (3,30). B2 for line from (3,30) to (4,0) or horizontal translation of it.