[问答题]
The London Eye is an observation whee
(e,joeb+v) x dc +fj9(chw6cz8uj5z1uiwi97teu:d + kpw0bnfn+m -ol in England with diameter of 120 metres. The wheel rota
n+uu9n em8k dof w10iuz7wj-bt5:+ pites at a constant speed and completes 2.5 rotations every hour. The bottom of the wheel is 15 metres above the ground.
A seat starts at the bottom of the wheel.
1. Find the maximum height above the ground of the seat.
After t minutes, the height h metres above the ground of the seat is given by
h(t)=75+a cos (b t), b>0 .
2. 1. Show that the period of h is 24 minutes.
2. Write down the exact value of b .
3. Find the value of a .
4. Sketch the graph of h , for $0 \leq t \leq 48$ .
5. In one rotation of the wheel, find the probability that a randomly selected seat is at least 110 metres above the ground.
