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
N=410,439
You can just type your problem into a calculator-- you're just finding out what 420,008-9,569 is. :)
So some quick tips for inequalities:
**What you do to one side you HAVE TO do it to the other 2**
**If you ever divide a negative number past the inequality signs, the signs FLIP!!**
(e.g. 2>-5x>25)
-2/5 <x < -5
I hope that this has helped!
Answer:
the height is : 2365.48 m
Step-by-step explanation:
hello :
h(t) = − 4.9 t 2 + 211 t + 94 .
the vertex of this parabola is : (-b/2a , h(-b/2a) when : a= -4.9 and b=211
-b/2a = -(211)/2(-4.9) = 21.53
h(21.53) = -4.9(21.53)²+211(21.53)+94 = 2365.48 m
The answer is <span>C. 50%.
The theoretical probability has nothing to do with the experiments. So, we will forget results of the experiment and think about theoretical probability. A coin has two sides - head and tail. The probability to get head is 1/2 = 0.5 = 50%. This is because if you toss the coin and you get head, head is one probability of two probability in total (head and tail). The same situation is with tail. Tail is .</span><span>one probability of two probability in total (head and tail).</span>
