Answer:
1) 0.785 cubic units
2) 696.91 cu feet - see explanation.
3) π/12
Explanation:
1) Volume of a cylinder with radius 1/2 and height of 1.
A cylinder is a circular prism. For any prism, to calculate its volume, we calculate the area of the shape of the prism, then multiply by its height. We all know how to calculate the area of a circle: A = π r², we have r (1/2). So...
A = π r² = π (1/2)² = π / 4 = 0.785 sq units
Now, we multiply this area by the height of the prism (h = 1):
V = A * h = 0.785 * 1 = 0.785 cubic units
2) Volume of a sphere, diameter of 11 ft
Since the diameter is 11 feet, that means the radius is 5.5 feet.
The sphere volume formula is:
V = (4/3)π r³, now that we have the radius, we can proceed:
V = (4/3)π r³ = V = (4/3)π (5.5)³ = V = (4/3)π * 166.375 = 221.833 π = 696.91 cu ft
However, that doesn't match any of your choices for answer.. so either you made an error in copying the answer choices or there was an error in the question... if we take a radius of 11 (instead of a diameter, we have 5575 cu ft, which is very close to one of your possible answers (5572).
3) Volume of a cone, radius of 1/2 and height of 1
The volume of a cone is found out with the formula:
V = (1/3)π r² h
We have all we need to calculate it:
V = (1/3)π (1/2)² (1) = (1/3) (1/4) π = (1/12) π = π/12
Prisms with a height of one are weird because it's basically like if they're a shape without height.