Force and Extension
Q1.
A student suspended a spring from a laboratory stand and then hung a weight from the spring.
Figure 1 shows the spring before and after the weight is added.
Figure 1
 
(a)     Which distance gives the extension of the spring?
 
Tick one box.	 	
from J to K	 	
from K to L	 	
from J to L	 	
(1)
(b)     The student used the spring, a set of weights and a ruler to investigate how the extension of the spring depended on the weight hanging from the spring.
Figure 2 shows that the ruler is in a tilted position and not upright as it should be.
Figure 2
 
How would leaving the ruler tilted affect the weight and extension data to be recorded by the student?
Use answers from the box to complete each sentence.
Each answer may be used once, more than once or not at all.
 
greater than	the same as	smaller than	
The weight recorded by the student would be _____________________ the actual weight.
The extension recorded by the student would be _____________________ the actual extension of the spring.
(2)
(c)     The student moves the ruler so that it is upright and not tilted.
The student then completed the investigation and plotted the data taken in a graph.
The student’s graph is shown in Figure 3.
Figure 3
 
Use Figure 3 to determine the additional force needed to increase the extension of the spring from 5cm to 15cm.
Additional force = ______________________ N
(1)
(d)     What can you conclude from Figure 3 about the limit of proportionality of the spring?
(1)
(e)     The student repeated the investigation with three more springs, K, L and M.
The results for these springs are given in Figure 4.
Figure 4
 
All three springs show the same relationship between the weight and extension.
What is that relationship?
 
Tick one box.	 	
The extension increases non-linearly with the increasing weight.	 	
The extension is inversely proportional to the weight.	 	
The extension is directly proportional to the weight.	 	
(1)
(f)     Which statement, A, B or C, should be used to complete the sentence?
Write the correct letter, A, B or C, in the box below.
A         a lower spring constant than
B         the same spring constant as
C         a greater spring constant than
From Figure 4 it can be concluded that spring M has      the other two springs.
(1)
(Total 7 marks)