6.6.5 SPM practice 3 (Linear Law) – Question 5


Question 5:
Use graph paper to answer this question.
Table 1 shows the values of two variables, x and y, obtained from an experiment. The variables x and y are related by the equation y = hkx + 1, where h and k are constants.

x
1
2
3
4
5
6
y
4.0
5.7
8.7
13.2
20.0
28.8
Table 1

(a) Based on table 1, construct a table for the values (x + 1) and log y. [2 marks]
(b) Plot log y against (x + 1), using a scale of 2 cm to 1 uint on the (x + 1) –axis and 2 cm to 0.2 unit on the log y-axis.
Hence, draw the line of best fit.    [3 marks]
(c) Use your graph in 9(b) to find the value of
(i) h.
(ii) k.  [5 marks]



Solution:
(a)
x + 1
2
3
4
5
6
7
log y
0.60
0.76
0.94
1.12
1.30
1.46

(b)



(c)
= hkx + 1
log y = log h + (x + 1) log k
log y = log k (x + 1) + log h
Y = log y
m = log k
X = (x + 1)
c = log h 

(i)
log h = y-intercept
log h = 0.26
h = 1.82

(ii)
logk=Gradient of the graph = 1.460.60 72 =0.172 k=1.486

 

1 thought on “6.6.5 SPM practice 3 (Linear Law) – Question 5”

Leave a Comment