An unknown length of copper wire and a 1.00-meter-long silver wire have the same cross-sectional area and resistance at 20°C. Calculate the length of the copper wire.

The length of the copper wire is 0.946 m.

Explanation:

Resistance ;

is the resistivity of the wire, is the length of the wire and A is the cross section area of the wire.

The magnitude of resistivity of copper wire is 1.68×10⁻⁸Ωm.

The magnitude of resistivity of silver wire is 1.59×10⁻⁸Ωm.

The length of silver wire is 1.00 m

The resistance of the copper wire is

The resistance of the silver wire is

Given that,

,

 []

m

The length of the copper wire is 0.946 m.

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =