Answer:
8.8 seconds
Step-by-step explanation:
Taking g = 9.81 m/s²
Convention: downwards positive
30 = -40t + 0.5(9.81)t²
4.905t² - 40t - 30 = 0
t = 8.846327763, -0.6913838279
t = 8.8s
Answer: 40, 48 and 56
8 x 4 = 32
8 x 5 = 40
8 x 6 = 48
8 x 7 = 56
2:1
2:3=1:3
as product of extremes = product of means
(2)(3):(1)(3)
6:3
D.
the angle size in an nonagon is 140°
