year 8 maths

Chapter review
335
16 This distance–time graph shows Mason’s cycle journey from home one morning.
Distance from home (km)
40
30
20
10
P
Q
0
8 a.m. 9 a.m.10 a.m. 11 a.m. noon 1 p.m. 2 p.m.
Time
R
a How far was Mason from home at 8:45 a.m.?
b What was Mason’s speed in the first hour of the journey?
c How many minutes was Mason’s first rest break?
d What was the furthest distance that Mason was from his home?
e Was Mason further away from home at point Q or point R?
f When had Mason ridden 60 km ?
g How far did Mason ride between points P and R?
h Describe each section of Mason’s journey from 9:30 a.m. to the finish. Include the distances,
times, speeds and any features.
Extended-response question
The Harrison family and the Nguyen family leave Wahroonga, Sydney, at 8 a.m. on Saturday morning for
a holiday in Coffs Harbour, which is 500 km north of Sydney.
The Harrisons’ 17 -year-old son drives for the first 2 hours at 90 km/h . They then stop for a rest of
1 1 hours. Mr Harrison drives the rest of the way, arriving at 3 p.m.
2
The Nguyen family drives the first 300 km in 3 hours and then have a break for 1 hour. Then the Nguyens
continue with no more stops and arrive in Coffs Harbour at 2:15 p.m.
a Using graph paper, draw a distance–time graph showing both journeys.
b How far apart were the two families at 10 a.m.?
c At what times did the Nguyens and Harrisons arrive at the halfway point?
d What was the Nguyen’s speed for the last section of their trip (correct to one decimal place)?
e Calculate the average speed of the Nguyen’s journey.
f At what time did the Harrisons resume their journey after their rest stop?
g How many kilometres did the Harrisons still have to cover after their rest break before arriving in
Coffs Harbour?
h For how long did Mr Harrison drive and at what speed?
i How far south of Coffs Harbour were the Harrisons when the Nguyen family arrived there?
j Calculate the cost of the petrol for each family’s trip if petrol cost is 139 c/L and the Harrison car’s
consumption is 9 L/100 km, and the Nguyen’s car uses 14 L/100 km .
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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