A thin, circular disc is made of lead and has a radius of 0.0350 cm at 20.0 °C. Determine the change in the area of the circle if the temperature is increased to 625.0 °C. The coefficient of linear thermal expansion for lead is 29.0 × 10^-⁶/C°. A)4.33 × 10^-⁵cm² B)1.36 × 10^-⁴cm² C)1.89 × 10^-⁴cm² D)3.19 × 10^-⁴cm² E)5.92 × 10^-⁴cm²

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Quizplus · Accepted Answer

The change in area can be calculated using the formula ΔA = 2αA₀ΔT, where α is the coefficient of linear expansion, A₀ is the initial area, and ΔT is the change in temperature. The initial area A₀ = πr² = π(0.0350 cm)². ΔT = 625.0 °C - 20.0 °C = 605.0 °C. Plugging in the values, ΔA = 2(29.0 × 10⁻⁶)(π(0.0350)²)(605) = 1.36 × 10⁻⁴ cm².

A Thin, Circular Disc Is Made of Lead and Has