Algebra, STD2 EQ-Bank 8 MC

The energy (\(E\)) required to heat water varies directly with the mass (\(m\)) of the water.

It takes 2100 joules of energy to heat 500 grams of water by 1°C.

Which equation represents the relationship between \(E\) and \(m\)?

Show Answers Only

\(A\)

Show Worked Solution

\(E \propto m\)

\(E=km\)

\(\text{When } E = 2100 \text{ and } m = 500:\)

\(2100\)	\(=k \times 500\)
\(k\)	\(=\dfrac{2100}{500}=4.2\)

\(\therefore\ E=4.2m\)

\(\Rightarrow A\)