Question

The area of a telescope lens is 6.679 × 103 mm2.

(a) What is the area in square feet (ft2)? Enter your answer in scientific notation.
(b) If it takes a technician 43.4 s to polish 1.46 × 102 mm2, how long does it take her to polish the entire lens?

Answer 1

Given:

Area of a telescope lens = 6.679 *
`10^(3) mm^(2)`

a)
`1mm^(2)  = 1.076*10^(-5) ft^(2)`

Area of lens = 6.679 *
`10^(3) mm^(2)`* 1.076*10^{-5} ft^{2}[/tex]

= 7.187 *
`10^(-2) ft^(2)`

b) Time taken to polish an area of 1.46 *
`10^(2) mm^(2)` = 43.4 s

Therefore, time taken to polish the entire lens

= 43.4 * 6.679 *
`10^(3) mm^(2)/ 1.46 * [tex]10^(2) mm^(2)`

= 1985 sec