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:
101
Step-by-step explanation:
If you add up all of the answers, it equals 101 due to the fact of just adding all of the x's together in a row.
Answer: the length is 87 feet
The width is 40 feet
Step-by-step explanation:
Let L represent the length of the playing field.
Let W represent the width of the playing field.
The playing field is rectangular. The formula for determining the perimeter of a rectangle is expressed as
Perimeter = 2(L + W)
The perimeter of a playing field for a certain sport is 254 ft. This means that
254 = 2(L + W)
L + W = 254/2
L + W = 127 - - - - - - - - - - - -1
The length is 47 ft longer than the width. This means that
L = W + 47
Substituting L = W + 47 into equation 1, it becomes
W + 47 + W = 127
2W + 47 = 127
2W = 127 - 47 = 80
W = 80/2 = 40
L = W + 47 = 40 + 47
L = 87
Answer:
$ 1,131.56
Step-by-step explanation:
1,250x85%=1,062.50
1,062.50x6.5=69.06
1062.50+69.06=1,131.56
Answer:
(x-1)(x-1) and (x-3)(x+2)
Step-by-step explanation:
