Answer:
7.5 ft³/min
Step-by-step explanation:
Let x be the depth below the surface of the water. The height, h of the water is thus h = 10 - x.
Now, the volume of water V = Ah where A = area of isosceles base of trough = 1/2bh' where b = base of triangle = 4 ft and h' = height of triangle = 1 ft. So, A = 1/2 × 4 ft × 1 ft = 2 ft²
So, V = Ah = 2h = 2(10 - x)
The rate of change of volume is thus
dV/dt = d[2(10 - x)]/dt = -2dx/dt
Since dV/dt = 15 ft³/min,
dx/dt = -(dV/dt)/2 = -15 ft³/min ÷ 2 = -7.5 ft³/min
Since the height of the water is h = 10 - x, the rate at which the water level is rising is dh/dt = d[10 - x]/dt
= -dx/dt
= -(-7.5 ft³/min)
= 7.5 ft³/min
And the height at this point when x = 8 inches = 8 in × 1 ft/12 in = 0.67 ft is h = (10 - 0.67) ft = 9.33 ft
This is for real questions
Answer:
The answer is 15.4
Step-by-step explanation:
hope this helps
1.3 + 12 =13.3+2.1=15.4
I cm = 60 km
2.5 cm = x km
60 * 2.5 = 150
2.5 cm = 150 km
Answer:
49<em>r</em>
Step-by-step explanation:
Written out it would be
49 x <em>r</em> = ?
But because mathmetitians like to write quickly, we say the answer above.
Key words are the product of 49 and the length of rope. So that means we are multipling which makes 49<em>r</em> the correct expression.