Step-by-step explanation:
initial speed = 272 ft/s
h = -16t² + 272t
a. 1120 = -16t² + 272t we change a bit into
16t² - 272t + 1120 = 0 then divide all with factor 16
t² - 17t + 70 = 0
(t - 10)(t - 7) = 0
t = 10 and t = 7
7 s when it goes up and 10 sec when the rocket goes down.
b. 1152 = -16t² + 272t we change a bit into
16t² - 272t + 1152 = 0 then divide all with factor 16
t² - 17t + 72 = 0
(t - 9)(t - 8) = 0
t = 9 and t = 8 sec
c. since the answer of a and b is:
7 sec and 8 sec the rocket goes up but at 9 sec and 10 sec the rocket goes down then we can take conclusion that the maximum height is reached at 8.5 s
so how long the rocket in the air?
goes up : 8.5 sec
goes down : 8.5 sec
total = 17 sec
The answer to this question is A
let l = lance, and a = alex.
so: l + a = 70
and l = 4a
Putting the value for l in the first equation:
4a +a = 70
5a = 70
a = 14.
So Alex has 14 pencils. And Lance has (70-14) 56 pencils.
And if each child gets half of Alex' pencils, then each child will have 7 pencils.
Given:
First, let us find two points from this equation.
We can set values of x and then solve for y.
Let us find the values of y when x = 1, 2, 3, 4, 5
We now have a set of points:
(1, 21)
(2, 16)
(3, 11)
(4, 6)
(5, 1)
Since the given plane is limited to values of 10 and -10, the points that we can plot are the points (4, 6) and (5, 1)
The graph would then look like this:
