4 The vertical position h in metres of a Ferris wheel is modeled using the function h t 6 sin t 5 7 where t is the time in seconds and h is the height in metres a Determine the period and amplitude of this function Explain the meaning of these quantities within the context of the question b Calculate the height at t 20 seconds c Determine the first time that the height is 11 m d When is the next time that this height is reached again