A model rocket is launched straight up from ground level with a speed of 34.2 m/s.
Assuming that the only force acting on the rocket after launch is the force of gravity,
a. How fast is the rocket going when it reaches a height of 22.5 m? (3 marks)
b. How long does it take the rocket to reach this height? (2 marks)
c. Why are there two answers to part b? Explain with a sketch. (1 mark