Answer:
a) 72.25sec
b) 6.25secs
c) after 10.5secs and 2 secs
Step-by-step explanation:
Given the height reached by the rocket expressed as;
s(t)= -4t^2 + 50t - 84
At maximum height, the velocity of the rocket is zero i.e ds/dt = 0
ds/dt = -8t + 50
0 = -8t + 50
8t = 50
t = 50/8
t = 6.25secs
Hence it will reach the maximum height after 6.25secs
To get the maximum height, you will substitute t - 6.25s into the given expression
s(t)= -4t^2 + 50t - 84
s(6.25) = -4(6.25)^2 + 50(6.25) - 84
s(6.25) = -156.25 + 312.5 - 84
s(6.25) = 72.25feet
Hence the maximum height reached by the rocket is 72.25feet
The rocket will reach the ground when s(t) = 0
Substitute into the expression
s(t)= -4t^2 + 50t - 84
0 = -4t^2 + 50t - 84
4t^2 - 50t + 84 = 0
2t^2 - 25t + 42 = 0
2t^2 - 4t - 21t + 42 = 0
2t(t-2)-21(t-2) = 0
(2t - 21) (t - 2) = 0
2t - 21 = 0 and t - 2 = 0
2t = 21 and t = 2
t = 10.5 and 2
Hence the time the rocket will reach the ground are after 10.5secs and 2 secs
Answer: the number must be placed in the box is 9
suppose: the number must be placed in the box is x
have:
5u + 3(4u - 6) = -3u -27 + 20u + x
⇔ 5u + 12u - 18 = -3u - 27 + 20u +x
⇔ 17u + 3u - 20u = -27 + 18 + x
⇔ 0 = x - 9
⇔ x = 9
Step-by-step explanation:
2,300 meters is the answer to your question.
Answer:
Make a graph
Step-by-step explanation: In order to plot points, you need to first make a graph. So you would make a graph and plot out the numbers on the line. Hopefully you know how to setup a graph and what goes on the x and y axis. So for the first one you would go left on the graph till you hit -3 and then down to -2 and then draw a point right there. For the second one you would go right to 2 and then up 4 and draw a point.
Answer:
18 dollars
Step-by-step explanation:
Marginal cost can be defined as the additional cost to produce every additional unit of a certain good. In mathematical terms;
Marginal cost = change in cost / change in quantity
For seven jackets, we have to find the difference between the cost of seven jackets and the cost of six jackets as follows
$101 - $83 = $18
Since the change in quantity is one, our marginal cost comes to $18.
