A 190 g air-track glider is attached to a spring. The glider is pushed in 9.8 cm and released. A student with a stopwatch finds that 14 oscillations take 18.5 sec.

What is the spring constant?

2 answers

frequency=1/2pi *sqrt(k/mass)
and frequency is 1/period.
frequency= oscillations/second

f=14osc/18.5sec=0.76Hz

T= 1/f

T= 2pi/w

1/0.76Hz=2pi/w

cross multiply

w=2pi*0.76= 4.775 rad/s

w=sqrt(k/m)

square both sides

w^2=k/m

w^2 * m = k

k = w^2 * m

you have "w" and you have mass. Plug them in and find the spring constant. Don't forget to convert the mass from grams to kilograms.