A 2.00-kg copper rod is 40.00 cm long at 23°C.If 50,000 J are transferred to the rod by heat,what is its change in length? (c_copper = 387 J/kg·°C and α_copper = 17 × 10^-6/°C)

Question

Quizplus · Accepted Answer

First, we need to calculate the change in temperature of the copper rod using the formula:
ΔT = Q/mcΔT
where Q is the heat energy transferred, m is the mass of the rod, c is the specific heat capacity of copper, and ΔT is the change in temperature.
ΔT = (50000 J) / (2 kg * 387 J/kg·°C) = 64.59°C
Next, we can calculate the change in length using the formula:
ΔL = αLΔT
where α is the coefficient of linear expansion for copper and L is the original length of the rod.
ΔL = (17 × 10^-6/°C) * (40 cm) * (64.59°C) = 0.0439 cm
Rounding to three significant figures yields an answer of 0.044 cm, which is choice B.

A 200-Kg Copper Rod Is 40