The spiral spring of a spring balance is 25.0cm long when 5N hangs on it and 30cm long, when the weight is 10N. What is the length of the spring if the weight is 3N assuming Hooke’s law is obeyed?
- 15.0cm
- 17.0cm
- 20.0cm
-
23.0cm
The correct answer is: D
Explanation
let the length be Lcm\(\frac{5 - 3}{25 - L}\) = \(\frac{10 - 5}{30 - 25}\)
L = 23cm