Graphing Relationships

Question

L=30+0.5

a. Use the Iowa students' rule to make a table and graph of sample (W,L) values for w=0 to 120 in steps of 20 grams.

b. How if a all, do the numbers 30 and 0.5 in the iowa students rule relate to the pattern of (W,L) values shown in the table and in the graph? What do they tell about the way the length of the cord changes as the attached weight changes?

Comments

HUH? WHAT THE? I don't get it. :-(

Answer 1

My guess is that this should read L=30+0.5W. The fixed length 30 is changed by the weight by the factor 0,5W where W is the weight.

To make a table prepare two columns headed W and L.

In the W column start at 0 and under it write 20, then 40, up to 120.

You should end up with 7 values: 0, 20, 40, 60, 80, 100, 120. In the L column, work out what L should be. For W=0 L=30. For W=20 L= 40; W=40, L=50. So the values of L are 30, 40, 50, 60, 70, 80, 90.

Now you can plot a graph where the horizontal W axis goes in steps of 20 and the vertical L axis goes in steps of 10 starting at 30. So the units only need marks on the axes at a multiple of 20 (W) and 10 (L).

 

The number 30 is the vertical intercept of the straight line graph. The number 0.5 is the slope.