Question

QUESTION 7Virus strands are very small in size. In a study Jenny has found 25 strands with a mass of 2.9 x 10-9 g/each. In a second study Rachel has found 45strands with a mass of 9.92 x 10-8 g/each. What was the average mass of all the virus strands? Keep answer in scientific notation.Enter the mantissa hereRound the mantissa to the nearest tenth.Enter the exponent of the base 10 hereEnter the unit symbol hereper one.

Answer 1

Jerry = 25 strand with mass of 2.9cx 10^-9 g/each

Rachel = 45 strand with mass of 9.92 x 10^-8 g/each

Average mass of all the virus strands =

$\begin{gathered} total\text{ strands = 25+45=70} \\ \text{Total mass = 9.92 }\times10^{-8}+2.9\times10^{-9} \\ =9.92\times10^{-8}+0.29\times10^{-9} \\ =(9.92+0.29)\times10^{-9} \\ =10.21\times10^{-9} \\ \text{Average = }\frac{\text{Total mass}}{\text{total strand}}=\frac{10.21\times10^{-9}}{70}=0.146\times10^{-9} \\ Average\approx0.2\times10^{-9} \end{gathered}$

The mantissa to the nearest tenth = 0.2

The exponent of the base 10 = -9

The unit symbol here per one = gram per one.