## Essential University Physics: Volume 1 (3rd Edition)

$3.18 \times 10^5$ N/m
We simplify the equation for period to find k to obtain: $k = \frac{4 \pi ^2 m}{T^2} = \frac{4 \pi ^2 (3.73 \times 10^5)}{6.8^2} =$ $3.18 \times 10^5$ N/m