Answer:
Explanation:
h(t) = - 6 cos (πt/30) + 7
determine value of t when h(t) = 3
3 = -6 cos (πt/30) + 7
-4 = -6 cos (πt/30)
cos (πt/30) = 2/3
πt/30 = 0.841069rad or 2π - 0.841069rad [in first cycle]
t = 0.841069*30/π = 8.03s or
t = 30/π (2π - 0.841069) = 30/π (5.44211630718) = 51.97s