Written Paper Section I Question 18-20 from the 2001 HSC Examination
Summary: Q18. Calculate the force acting on a projectile when it is at its maximum height after being fired from a cannon and the time it takes to reach the ground from its maximum height. Describe and compare the vertical forces at the object's maximum height with the forces on an identical object attached to a mechanical arm and moved at a constant speed in a vertical half-circle. Q19. Outline how Einstein’s Theory of Special Relativity explains the result of the Michelson–Morley experiment. Q20. Explain why transformers are used in an a.c. network between the generating stations and the final consumer.