A spring of unknown force constant is attached to a rod so that it hangs vertically. With no mass attached, the spring has a length of 12.0 cm. When a student attaches a mass of 50 grams, the spring stretches to a length of 18.0cm. Determine the force constant for this spring.

Answer 1

F = m*g = 0.05kg * 9.8N/kg = 0.49 N.

d = 18-12 = 6 cm = 0.06 m.

k = 0.49N/0.06m = 8.17N/m.