A Fire Hose Is Turned on the Door of a Burning

question 69

Multiple Choice

A fire hose is turned on the door of a burning building in order to knock the door down.This requires a force of 1000 N.If the hose delivers 40 kg of water per second,what is the minimum velocity of the stream needed to knock down the door,assuming the water doesn't bounce back?

• A)15 m/s
• B)20 m/s
• C)25 m/s
• D)30 m/s

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Definitions:

Null Hypothesis

A statement that there is no difference or effect, typically to be tested against an alternative hypothesis proposing a difference or effect.

Significance Level

The probability of rejecting the null hypothesis when it is actually true; a threshold chosen by the researcher to indicate the level of evidence needed to reject the null hypothesis.

Kruskal-Wallis Test

A nonparametric statistical test used to compare three or more independent samples to determine if they originate from the same distribution.

P-value

The probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true.