An aluminium container of mass 0.15 kg contains 0.25 kg of ethanol.
The specific heat capacity of aluminium is 900 J kg−1 ∘C−1900\text{ J kg}^{-1}\text{ }^{\circ}\text{C}^{-1}900 J kg−1 ∘C−1 and the specific heat capacity of ethanol is 2400 J kg−1 ∘C−12400\text{ J kg}^{-1}\text{ }^{\circ}\text{C}^{-1}2400 J kg−1 ∘C−1.
How much energy, in joules, is needed to raise the temperature of the aluminium container and the ethanol by 15 ∘C15\text{ }^{\circ}\text{C}15 ∘C?
(0.15×900×15)−(0.25×2400×15)(0.15 \times 900 \times 15) - (0.25 \times 2400 \times 15)(0.15×900×15)−(0.25×2400×15)
(0.15×900×15)+(0.25×2400×15)(0.15 \times 900 \times 15) + (0.25 \times 2400 \times 15)(0.15×900×15)+(0.25×2400×15)
(0.25+0.15)×(2400+9002)×15(0.25 + 0.15) \times \left(\frac{2400 + 900}{2}\right) \times 15(0.25+0.15)×(22400+900)×15
(0.25+0.15)×(2400+900)×15(0.25 + 0.15) \times (2400 + 900) \times 15(0.25+0.15)×(2400+900)×15
119 exam-style questions on CIE IGCSE Physics 2.2.2a Internal energy and temperature. Each one has a worked solution and a mark scheme showing where the marks go.