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saul85 [17]
3 years ago
7

1) A light bulb takes in 30 of energy per second. It transfers 3j as use

Chemistry
1 answer:
natta225 [31]3 years ago
8 0

Answer:

\boxed{\text{10 \%}}

Explanation:

The formula for efficiency is  

\begin{array}{rcl}\text{Efficiency} & = & \dfrac{\text{useful energy out}}{\text{energy in}} \times 100 \,\% \\\\\eta & = & \dfrac{w_{\text{out}}}{w_{\text{in}} } \times 100 \,\%\\\end{array}

Data:

Useful energy =  3 J

Energy input  = 30 J

Calculation:

\begin{array}{rcl}\eta & = & \dfrac{\text{3 J}}{\text{30 J}} \times 100 \,\%\\\\\eta & = & 10 \, \%\\\end{array}\\\text{ The efficiency is }\boxed{\textbf{10 \%}}

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Answer:

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Answer:

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Explanation:

<em>A chemist makes 660. mL of magnesium fluoride working solution by adding distilled water to 230. mL of a 0.00154 mol/L stock solution of magnesium fluoride in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.</em>

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