A car of mass 500 kg is moving at a speed of 1.2 m/s. A man pushes the car, increasing the speed to 2 m/s. How much work did the man do?
A. 640 J
B. 360 J
C. 1360 J
D. 1000 J

Amass attached to a spring is displaced from its equilibrium position by 5cm and released. the system then oscillates in simple harmonic motion with a period of 1s. if that same mass–spring system is displaced from equilibrium by 10cm instead, what will its period be in this case