A 21.6-kg cube made from aluminum is at its melting temperature of 660℃. If you were to add 8000 kJ worth of energy as heat, what percent of the block melts? You might need the following: α = 23.0 ✕ 10-6 K-1, β = 69.0 ✕ 10-6 K-1, c = 900 J/kgK, LF = 3.98 ✕ 105 J/kg

Question

Celia Ramos

Physics

21 April, 20:33

A 21.6-kg cube made from aluminum is at its melting temperature of 660℃. If you were to add 8000 kJ worth of energy as heat, what percent of the block melts? You might need the following: α = 23.0 ✕ 10-6 K-1, β = 69.0 ✕ 10-6 K-1, c = 900 J/kgK, LF = 3.98 ✕ 105 J/kg

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Answers (1)

Know the Answer?

Ayana Wolfe · Answer 1

The percentage of block melts is 93.1 %

Explanation:

Let the block melted be m₁

Given: LF = 3.98 * 10⁵ J/kg

Amount of heat added, Q = 8000 KJ = 8*10⁶ J

Using:

Q = m₁*LF

8*10⁶ = m₁ * 3.98 * 10⁵

m₁ = 20.1 kg

So, the percentage of block melts, % = m₁/m * 100

% = 20.1 / 21.6 * 100 = 93.1 %

The percentage of block melts is 93.1 %