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:
1) yes and no you cant tell most the time but using common sense you can tell.
2)Yards, feet, inches, pounds, quarts, and miles are all part of the English system of measures. they are related because they all deal with unit of distance
3), the distance of a road is how long the road is. In the metric system of measurement, the most common units of distance are millimeters, centimeters, meters, and kilometers. they are related because they also deal with distance in metrics.
Step-by-step explanation:
Answer: 4y/(y+3)
Explanation:
{(2y)(4y-12)}/{(y-3)(2y+6)}
= (8y^2 - 24y)/(2y^2 + 6y - 6y - 18)
= (8y^2 - 24y)/(2y^2 - 18)
= {8y(y-3)}/{2(y+3)(y-3)}
= 2 * 4y/{2(y+3)}
= 4y/(y+3)
Answer:
9
(z)
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Answer:
Step-by-step explanation:
i really wish i knew the answer
