The extension of a stretched string is directly proportional to its tension. If the extension produced by a tension of 8 Newton’s is 2cm, find the extension produced by a tension of 12 newton’s.
A
2
B
1
C
0
D
3
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
Let the extension be E and the tension be T.
Then \(E \propto T\)
\(E = kT\)
when T = 8N, E = 2cm
\(2 = k \times 8\)
\(k = \frac{2}{8} = 0.25\)
\(\therefore E = 0.25T\)
when T = 12N, \(E = 0.25 \times 12 = 3cm\)
Source: Myschool Past Questions Archive (Record #40657)