Ster R.
asked • 03/02/20Which of the following are identical amounts of energy?
1kJ and 1 kcal
1kJ and 239 cal
1kJ and 1 Cal
4.184 J and 1 kcal
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1 Expert Answer
J.R. S. answered • 03/02/20
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Ph.D. University Professor with 10+ years Tutoring Experience
The relationship between joules (J) and calories (cal) is that 1 cal = 4.184 J
Also, 1 Cal (cap. C) is 1 kilocalories = 1000 cal
So, the identical amounts of energy would be
1 kJ and 239 cal because 1kJ is 1000 J and 1cal is 4.184 J. So... 1000 J x 1 cal/4.184 J = 239 cal
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Eli T.
4.184 Joules (J) is equal to 1 calorie (Cal). Knowing this, we can rule out the last pair because 1 kCal is not equal to 1 Cal. We can then test whether the other three pairs are equal amounts by converting 1kJ to Cal: 1kJ*(1000 J/1kJ) = 1000 J -> 1000 J*(1 Cal/4.184 J) = 239 Cal Out of the first three pairs, only the second pair is a correct unit conversion, i.e. identical amounts of energy. The answer is that only 1kJ and 239 Cal are identical amounts of energy.03/02/20