A Kilogram of Water (C = 4

question 28

Multiple Choice

A kilogram of water (c = 4.186 kJ/kg °C) is stirred using a 400−watt device for 5 minutes. At the end of this time the temperature of the water has increased by 15°C. How much heat was lost to the surroundings?

• A) 90.1 kJ
• B) 57.2 kJ
• C) 82.6 kJ
• D) 38.9 kJ

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Definitions:

Level Of Significance

The probability of rejecting the null hypothesis in a statistical test when it is actually true, used as a criterion for judging whether an observed effect is statistically significant.

Upper-tail Area

The area under the probability density function of a continuous random variable to the right of a specified value, used in significance testing.

Pooled Proportion Estimate

A method used to estimate the combined proportion from two or more groups, assuming that the underlying proportions across groups are the same.

Null Hypothesis

A statistical hypothesis that assumes no significant difference or effect exists among the variables studied.