posted by Anonymous .
A 880 kg car strikes a huge spring at a speed of 20 m/s (Fig. 11-50), compressing it 15.0 m.
(a) What is the spring constant of the spring? (Found this, it was 1564.44)
(b) How long is the car in contact with the spring before it bounces off in the opposite direction? <--Need help with this one, thanks!