Matching data, graphs and experiments

Teacher activity

The following tables and graphs represent five different relationships. Which relationships?

X / Y /
0 / 7,7
15 / 5,6
30 / 3,8
45 / 2,8
60 / 2,1
75 / 1,5
90 / 1,1
105 / 0,8
120 / 0,6
135 / 0,4 / Relationship: ......
/ X / Y /
20 / 2,5
30 / 5,6
40 / 10,3
50 / 15,7
60 / 23,3
70 / 30,1
80 / 41,6
90 / 51,2
100 / 61,1
110 / 73,7 / Relationship: ......
X / Y /
12,5 / 1,35
35,0 / 2,67
40,0 / 4,27
50,0 / 5,29
51,5 / 5,69
64,5 / 6,93
99,5 / 10,6
Relationship: ......
/ X / Y /
3,5 / 10,6
6,5 / 5,65
10,0 / 3,65
13,5 / 2,77
16,5 / 2,24
20,0 / 1,85
23,5 / 1,58
26,5 / 1,37
30,0 / 1,22
33,5 / 1,09 / Relationship: ......
X / Y /
15 / 1976
20 / 1021
30 / 425
40 / 256
60 / 118
80 / 66
100 / 42
Relationship: ......
/ Possible relationships:
·  proportional
·  inversely proportional
·  quadratic
·  inversely quadratic
·  exponential

Tables and graphs result from five experiments.

Which relationship belongs to which experiment?

Torsion swing and ropes
A bar is suspended from two strings. The bar rotates in a horizontal plane (torsion). The distance between the two strings is changed.
What is the relationship between the distance between the strings and the rotation time?
Relationship: ......
Torsion swing and ropes
A bar is suspended from two strings. The bar rotates in a horizontal plane (torsion). The length of the bar is changed.
What is the relationship between the length of the bar and the rotation time?
Relationship: ...... /
Braking distance car
The braking distance of a car is measured at different speeds. During the test, the mass and braking force remain constant.
What is the relationship between the speed of the car and the braking distance?
Relationship: ...... /
Head of beer
Immediately after tapping a beer the bottom of the head crawls slowly upwards. The decrease of the thickness of the head is caused by collapsing bubbles. This is a random process.
What is the relationship between the thickness of the head and time?
Relationship: ...... /
Luminosity
The light intensity of a bulb is measured with a light sensor. The distance from the sensor to the lamp is changed.
What is the relationship between the distance and the light intensity?
Relationship: ...... /