A Lab Assistant Drops a 400 $15.0 ^ { \circ } \mathrm { C }$

question 141

Multiple Choice

A lab assistant drops a 400.0-g piece of metal at 100.0°C into a 100.0-g aluminum cup containing 500.0 g of water at $15.0 ^ { \circ } \mathrm { C }$ In a few minutes, she measures the final temperature of the system to be 40.0°C. What is the specific heat of the 400.0-g piece of metal, assuming that no significant heat is exchanged with the surroundings? The specific heat of this aluminum is 900.0 J/kg ? K and that of water is 4186 J/kg ? K.

• A)1900 J/kg ? K
• B)2270 J/kg ? K
• C)3300 J/kg ? K
• D)3800 J/kg ? K
• E)4280 J/kg ? K

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Definitions:

Break Even

The point at which total costs and total revenues are equal, meaning there is no profit or loss.

Operating Leverage

A measure of how revenue growth translates into growth in operating income, indicating the ratio of fixed costs to variable costs.

Contribution Margin

The amount remaining from sales revenue after variable expenses have been deducted, indicating how much contributes to the fixed costs and profits.

Scatter Diagram

A graph used in statistics to visually display and assess the possible relationship between two numerical variables.