i) A car of 950 kg hits a huge spring at a speed of 22 m/s, compressing it 5.0 m. Determine the spring constant of the spring and explain how long is the car in contact with the spring before it bounces off in the opposite direction?
ii) A simple pendulum oscillates with the frequency f. Determine its frequency if it is accelerated at 0.5g (a) upward, (b) downward?