A stone gets stuck in the tire of a tractor plowing a field. The following sinusoidal equation models the height of the stone as the tire turns:
y = 70sin(1.4x + 4.71) + 70
where y represents the height of the stone with respect to the ground (in cm) and x represents the time (in seconds).
- How long does it take for the tire to make one complete rotation?
- For how many seconds (to 2 decimal places) is the stone at least 120 cm above the ground during the first rotation of the tire?