Question

Can someone please help with number 7

Answer 1

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