Given
d(t) = 0.8t ^2
t= 5 secs
d(5) = 0.8(5)^2 = 0.8 * 25 = 20
t= 10 secs
d(10) = 0.8(10)^2 = 0.8 * 100 = 80
20 m / 5 secs = 4 meters per sec
80 m / 10 sec = 8 meters per sec
4 mps + 8 mps = 12 mps
12 mps / 2 = 6 mps
6 mps is the average speed of the rock between 5 and 10 sec after being dropped
-4x > 16
Divide -4 on both sides. Don't forget to flip sign since we are dividing by a negative number.
x < -4
The angle j plus angle k would equal
30j+k
