Question

Which quantity of heat is equal to 200. joules?
(1) 20.0 kJ (3) 0.200 kJ
(2) 2.00 kJ (4) 0.0200 kJ

Answer 1

The answer is (3) 0.200 kJ. The conversion between joules and kilojoules is that 1 joule = 0.001 kilojoules. So we can easily get the answer that 200 joules equals to 0.200 kJ.

Answer 2

Joules is the unit to measure energy.

Heat is a form of energy that can be measured using Joules.

We are asked to find the quantity of heat in kJ. so we have to convert joules (J) to kilo joules (kJ)

1000 joules is equivalent to 1 kJ

then 1 J = 1/1000 kJ

therefore

200 J is equivalent to $\frac{1}{1000} *200 = \frac{200}{1000} = 0.200$ kJ

answer is 3) 0.200 kJ