A spring has an unstretched length of 13 cm. When an77 g ball is hung from it, the length increases by 7.0 cm. Then the ball is pulled down another 7.0 cm and released.

What is the spring constant of the spring?

The force of gravity on the ball = the force on the spring

Known Variable:

M(mass): 77 g or .077 kg

g(gravity) = g

ΔL = .07 m

ΔL= Mg/k

solve for K:

K=Mg/ΔL

K= (.071) x (9.8)/.07 m

= 10.78 or

11 N/m

What is the period of the oscillation?

f=1/2π√(k/m)

= 1/2π√(10.48 /.071 kg)

=.53 s