The total length of a spring when a mass of 20g is hung from its end is 14cm, while its total length is 16cm when a mass of 30g is hung from the same end. Calculate the unstretched length of the spring assuming Hooke’s law is obeyed.
-
A.
9.33cm -
B.
10.00cm -
C.
10.66cm -
D.
12.00cm -
E.
15.00cm
Correct Answer: Option B
Explanation
Let unstretched length = L
e1 = 14 – L and e2 = 16 – L
Using, (frac{m_1}{e_1}) = (frac{m_2}{e_2})
(frac{20}{14 – L}) = (frac{30}{16 – L})
L = 10cm