Question

An observatory has the shape of a right circular cylinder surmounted by a hemisphere. If the radius of the cylinder is 14 ft and its altitude measures 30 ft, What is the surface area of the observatory? If 1 gal of paint covers 300 ft², how many gallons are needed to paint the surface if it requires two coats?

Answer 1

Answer:

surface area is 3870.44 ft^2

you would need 13 gallons of paint

Step-by-step explanation:

the equation for surface area of a cylinder is A=2πr(r+h) -> r is the radius and h is the height or altitude

So in this problem you would plug in 14 for r and 30 for h and you get 3870.44 then your units are ft^2 because it is area which is always squared

To find out how many gallons of paint to use, you divide the surface area by the area the paint covers so you would do

3870.44 / 300 which gives you about 12.9 gallons but you cannot buy 12.9 gallons of paint so round it up to 13

Answer 2

Answer:

surface area is 3870.44 ft^2

you would need 13 gallons of paint

Step-by-step explanation:

the equation for surface area of a cylinder is A=2πr(r+h) -> r is the radius and h is the height or altitude

So in this problem you would plug in 14 for r and 30 for h and you get 3870.44 then your units are ft^2 because it is area which is always squared

To find out how many gallons of paint to use, you divide the surface area by the area the paint covers so you would do

3870.44 / 300 which gives you about 12.9 gallons but you cannot buy 12.9 gallons of paint so round it up to 13