F.4 Phy 2條單位轉換題 20分 急

你好～～

以下是本人的意見，盼有用～

1) Density of water = 1g cm^(-3) = 1 / 1000 kg cm^(-3) = 0.001 kg cm^(-3)

And 0.001 kg cm^(-3) = 0.001 / (0.01)^3 kg m^(-3) = 1000 kg m^(-3)

So, Mass of 2m^3 of water = 1000 * 2 kg = 2000kg

2) µm = 10^(-6) m

As the cross-sectional area of a wire is a circle, we should use the formula of finding a circle to solve this question.

(* π = pi)

By Area = π * r^2

Cross-sectional area = π * (280µm / 2)^2

= π * [140 * 10^(-6)]^2 m^2

= π * [19600 * 10^(-12)] m^2

= π * 1.96 * 10^(-8) m^2

= 1.96 * 10^(-8) * π m^2

希望以上答案可以幫到你～～～～～