Answer:
The radius of the hole is 0.42 feet
Explanation:
Let us revise the rule of the volume of a cylinder
→ V = πr²h, where
→ V is the volume of the cylinder in a cubic unit
→ r is the radius of the base of the cylinder
→ h is the height of the cylinder
Let us solve our question
→ The volume of the cylinder is 3800 cubic feet
→ The height of the cylinder is 1.3 miles
Very Important Note: dimensions must have the same unit
→ Change the mile to feet
→ There are 5280 feet in 1 mile
→ Multiply 1.3 miles by 5280 to change it to feet
→ The height = 1.3 × 5280 = 6864 feet
Let us substitute the values of V and h in the rule above
∵ V = πr²h
∵ V = 3800 ft³
∵ h = 6864 ft
∴ 3800 = πr²(6864)
→ Divide both sides by 6864π to find r²
∴ r² = 0.1762205081
→ take √ for both sides to find r
∴ r = 0.4197862648
→ Round it to the nearest hundredth
∴ r = 0.42 ft
The radius of the hole is 0.42 feet