Answer:
what did u get the answers
Let x represent the number of liters of 50% acid Theresa puts into the mix. The the number of liters of 30% acid will be (420-x). The total amount of acid in the final solution will be ...
0.50x + 0.30(420-x) = 0.45(420)
0.20x + 126 = 189 . . . . . . . . . . . . . . . simplify
0.20x = 63 . . . . . . . . . . . . . . . . . . . . . subtract 126
x = 63/0.20 = 315 . . . . . . . . . . . . . . . liters of 50% solution
(420-x) = 420-315 = 105 . . . . . . . . . liters of 30% solution
Theresa should mix ...
105 liters of 30% solution
315 liters of 50% solution
90°+b+b =180
90°+ 2b=180
2b=180-90
2b= 90
<u>2</u><u>b</u><u>=</u><u>9</u><u>0</u>
<u>2</u> = 2
b=45°
ave tried I don't know if its correct
Answer:
It will take the boulder approximately 4.28 seconds to hit the road
Step-by-step explanation:
The given height of the cliff from which the boulder falls, h = 90 feet
The equation that can be used to find the time it takes the boulder to fall is h = u·t + (1/2)·g·t²
Where;
h = The height of the cliff = 90 ft.
u = The initial velocity of the boulder = 0 m/s (The boulder is assumed to be at rest when it falls)
g - The acceleration due to gravity ≈ 9.81 m/s²
t = How long it will take for the boulder to hit the road below
Plugging in the values gives;
90 = 0 × t + (1/2)×9.81×t² = 4.905·t²
∴ t = √(90/4.905) ≈ 4.28
The time it takes the boulder to hit the road, t ≈ 4.28 seconds.
