How Much Paint for a Hemispherical Dome Using Differentials?

[maladroit]

Homework Statement

Use differentials to estimate the amount of paint needed to apply a coat of paint 0.05 cm thick to a hemispherical dome with diameter 54 m.

Homework Equations

dy=dy/dx *dx

Surface area of a hemishpere=2pi*r^2

The Attempt at a Solution

dy=4pi*r dx
dy=4pi*27 *.05
dy=16.96

 

[Dick]

You want to express all of your numbers in the same units. 0.05 cm is not the same as 0.05 m.

 

[maladroit]

genius...thank you!