DISTANCE, SPEED, TIME

Junior Cert Revision

The graph below shows the distance travelled along a track by Ann over the course of a race.The graph is in two sections, labelled A and B.

Show that Ann’s speed in section A is 5 metres per second.

2016 JCHL Paper 1 – Question 5 (a) (i)

Speed =Distance

Time

Speed =300

60

Speed = 5 m/s

Distan

ceTime

Find Ann’s speed in section B, in metres per second.

2016 JCHL Paper 1 – Question 5 (a) (ii)

Speed =Distance

Time

Speed =100

40

Speed = 2.5 m/s

Distan

ce

Time

Table 1 shows graphs of the distance travelled along the track by Bill, Claire, and Dee during the same race. Each person’s name is written next to their graph.Table 2 shows graphs of the speed of Bill, Claire, and Dee during the race.Complete Table 2, by writing the correct name next to each graph.

2016 JCHL Paper 1 – Question 5 (b)

Claire

Dee

Bill

Claire has a constant speed the throughout the race.

Bill increases his speed throughout the race.

Dee decreases her speed throughout the race.

The graph below shows the distance Erik travelled along the track during the same race.Sketch the graph of Erik’s speed during the race on the axes below.

2016 JCHL Paper 1 – Question 5 (c)

Along this section of track Erik decreased his speed, stopped for a period of time (his distance did not increase during this time) and then increased his speed again.

A train leaves Cork at 09:05 and arrives in Dublin at 12:25.The distance from Cork to Dublin is 250 km.Find the average speed of the train in km/h.

2003 LCOL Paper 1 – Question 1 (a)

Speed =Distance

Time

Speed =250

313

Speed = 75 km/h

12: 25 −09: 0503: 20

= 3 hours 20 mins

= 31

3hours

Finding the time taken.

𝑆 𝐷

Car A:

𝑇 =𝐷

𝑆

=70

50= 1.4 hours

Car B:

𝐷 = 𝑇 × 𝑆= 1.4 × 45= 63 km

70 km

50 km/h

45 km/h

?

Car A and Car B set off from a starting point 𝑆 at the same time. They travel the same route to destination 𝐷, which is 70 km away. Car A travels at an average speed of 50 km/h and car 𝐵 travels at an average speed of 45 km/h.How far will car 𝐵 have travelled by the time car 𝐴 arrives at destination 𝐷?

2013 JCHL Paper 1 – Question 6

Car A and Car B set off from a starting point 𝑆 at the same time. They travel the same route to destination 𝐷, which is 70 km away. Car A travels at an average speed of 50 km/h and car 𝐵 travels at an average speed of 45 km/h.How far will car 𝐵 have travelled by the time car 𝐴 arrives at destination 𝐷?

2013 JCHL Paper 1 – Question 6

Car A: Car B:

Time =Distance

Speed

First find the time taken for Car A to travel the 70 km.

=70

50= 1.4 hours

Distance = Time × Speed

= 1.4 × 45= 63 km

Now calculate the distance travelled by Car B in that time.

A man travels from Arklow to Blanchardstown, a distance of 90 km. He leaves Arklow at 09:25 and arrives in Blanchardstown at 10:55.

Calculate his average speed for the journey.

2009 JCHL Paper 1 – Question 1 (c) (i)

=112

64= 1.75 hours= 1 hour 45 minutes

Time =Distance

Speed

He continues from Blanchardstown to Cootehill, a distance of 112 km. He increases his average speed by 4 km/h for this section of his journey.

At what time does he arrive in Cootehill?

2009 JCHL Paper 1 – Question 1 (c) (ii)

10: 55 −09: 2501: 30

1.5 hours

=90

1.5= 60 km/h

Speed =Distance

Time

Finding the time taken.

Find the arrival time.

10: 55 +01: 4512: 40

Error = 60 − 57 = 3

=3

57× 100

= 5.3%

110 km/h = 105.3%110

105.3× 100 = 100%

104.5 km/h = Actual= 80 × 4320 km

80 km/h = 105.3%80

105.3× 100 = 100%

75.97 km/h = Actual

𝑖

The speedometer in a car is faulty. When the car is actually travelling at 57 km/h, the speedometer reads 60 km/h.

(i) Calculate the percentage error, correct to one decimal place.(ii) If the percentage error is the same at all speeds, at what speed is the car actually travelling when the speedometer reads 110 km/h?Give your answer correct to one decimal place.(iii)The driver is not aware of the fault. He calculates that if he travels at an average speed of 80 km/h as shown on the speedometer, he will reach his destination in four hours.

How long, correct to the nearest minute, will it actually take him to reach his destination?

2011 LCOL Paper 1 – Question 1 (c)

𝑖𝑖

𝑖𝑖𝑖Percentage Error =

Error

Actual× 100

110 km/h is 5.3% more than the actual speed.

First calculate the actual speedusing method from part (ii)

Find the distance based off hiscalculation

Now calculate the time takento travel this distance usingactual speed.

Time =Distance

Speed

=320

75.97= 4.21 hours

= 4 hours 13 minsDistance = Speed × Time

Alice frequently travels from her home to Cork, a distance of 85 km. The journey usually takes 1 hour 15 minutes.(i) Find her average speed in kilometres per hour for the journey.(ii) On a day of very heavy rain her average speed on a 28 km section

of the journey was reduced to 35 km/h.How long did this section of the journey take on that day?

(iii) How much longer did the total journey take on that day, if she completed the rest of the journey at her usual average speed?

Give your answer correct to the nearest minute.

2008 LCOL Paper 1 – Question 2 (a)

1 hour 15 minutes= 75 minutes

=75

60hours

= 1.25 hours

=85

1.25= 68 km/h

=28

35= 0.8 hours= 0.8 × 60 minutes= 48 minutes

85 − 28 = 57

=57

68hours

=57

68× 60

= 50.29 minutes

𝑖 𝑖𝑖 𝑖𝑖𝑖Time =

Distance

Speed

Must change hours andminutes into decimal

Speed =Distance

Time

Calculate the distance travelled at her usual speed and convert to minutes.

Calculate the total time taken.

48 + 50.29 = 98.29 minutes

98.29 −75

23.29 minutes

23 minutes longer