Answer:
∫∫∫1 dV=4\sqrt{3}π
Step-by-step explanation:
From Exercise we have
z=6-x^{2}-y^{2}
z=x^{2}+y^{2}
we get
2z=6
z=3
x^{2}+y^{2}=3
We use the polar coordinates, we get
x=r cosθ
y=r sinθ
x^{2}+y^{2}&=r^{2}
r^{2}=3
We get at the limits of the variables that well need for our integral
x^{2}+y^{2}≤z≤3
0≤r ≤\sqrt{3}
0≤θ≤2π
Therefore, we get a triple integral
\int \int \int 1\, dV&=\int \int \left(\int_{x^2+y^2}^{3} 1\, dz\right) dA
=\int \int \left(z|_{x^2+y^2}^{3} \right) dA
=\int \int\ \left(3-(x^2+y^2) \right) dA
=\int \int\ \left(3-r^2 \right) dA
=\int_{0}^{2\pi}\int_{0}^{\sqrt{3}} (3-r^2) dr dθ
=3\int_{0}^{2\pi}\int_{0}^{\sqrt{3}} 1 dr dθ-\int_{0}^{2\pi}\int_{0}^{\sqrt{3}} r^2 dr dθ
=3\int_{0}^{2\pi} r|_{0}^{\sqrt{3}} dθ-\int_{0}^{2\pi} \frac{r^3}{3}|_{0}^{\sqrt{3}}dθ
=3\sqrt{3}\int_{0}^{2\pi} 1 dθ-\sqrt{3}\int_{0}^{2\pi} 1 dθ
=3\sqrt{3} ·2π-\sqrt{3}·2π
=4\sqrt{3}π
We get
∫∫∫1 dV=4\sqrt{3}π
The correct answer is 21π/5
Explanation:
The arc length of a circle is given as = radius × angle subtended by the arc at centre.
Here, r = 7 cm.
θ = 3π/5
Therefore, arc length, l = rθ = 7×3π/5 = 21π/5
Answer:
The average rate is 35 miles per hour
Step-by-step explanation:
To get from town A to town B takes 3 hours. The distance is 100 miles
To get from town B to town c takes 1 hours. The distance is 40 miles
To find the average rate , we need to find the total distance and divide by the total time
Total distance = 100 + 40 = 140 miles
Total time = 3 hrs + 1 hr = 4 hours
distance = rate * time
140 miles = rate * 4 hours
140/4 = rate
35 = rate
The average rate is 35 miles per hour
