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 answer is 3 , 1 , 2 .
Step-by-step explanation:
I will give an example.
e.g.
x² + 3x + 2
Step 3 :
Set the equation equal to zero :
x² + 3x + 2 = 0
Step 1 :
Completely factor the equation :
x² + x + 2x + 2 = 0
x(x+1) + 2(x+1) = 0
(x+2)(x+1) = 0
Step 2 :
Set each factor equal zero and then solve for the variable :
(x+2)(x+1) = 0
x + 2 = 0
x = -2
x + 1 = 0
x = -1
Answer:
Step-by-step explanation:
In a right angled triangle, we have perpendicular, hypotenuse and base.
The hypotenuse is the longest side and opposite to the right angle. the side having 90 degree angle is perpendicular.
Applying formulas we can find the values:
the formulas are : cos (Ф) = Base / hypotenuse
sin (Ф) = Perpendicular / hypotenuse
tan (Ф) = Perpendicular / Base
11. cos z
cos z = Base / hypotenuse
cos z = 12/15
12. cos C
cos C = base / hypotenuse
cos C = 38/45
13. tan C
tan C = Perpendicular/ Base
tan C = 40/30
14. tan A
tan A = Perpendicular/ Base
tan A = 21/20
15. tan C
tan C = Perpendicular/ Base
tan C = 12/35
16. tan X
tan X = Perpendicular/ Base
tan X = 30/40
17. sin Z
Sin Z = Perpendicular / Hypotenuse
sin Z = 35/37
18. sin z = Perpendicular / Hypotenuse
sin z = 30/50
If the width of the cardboard = x cm then its length is given by x + 8 cm.
Then the length of the box will be x + 8 - 2(2) = x + 4
and the width = x - 2(2) = x - 4 cm The height is 2 cm
Volume = h*w*l = 2(x - 4)(x + 4) = 256
2(x^2 - 16) = 256
x^2 - 16 = 128
x^2 = 144
x = 12 cm
Dimensions of the box are:-
length = 12 + 4 = 16cm
width = 12 - 4 = 8 cm
height = 2 cm
Rewrite 9 1/6 divided by 5/6 as follows:
55 6
---- * -----
6 5
Reducing this produces the desired quotient, 11.
