When 90 kJ is removed from a 2-kg copper bar, its temperature drops from 200°C to 85°C. The specific heat of copper is
q = mass Cu x specific heat Cu x ((Tfinal-Tnitial)
use q = 90,000 J.
Use mass Cu as 2000g
specific heat comes out in J/g*C
In order to find the specific heat of copper, we can use the formula:
Q = mcΔT
Where:
Q is the amount of heat energy transferred
m is the mass of the object
c is the specific heat capacity
ΔT is the change in temperature
Given that 90 kJ (90,000 J) is removed from a 2-kg copper bar, and the temperature drops from 200°C to 85°C, we can substitute these values into the formula:
90,000 J = (2 kg)(c)((85°C) - (200°C))
Let's rearrange the equation to solve for c:
c = (90,000 J) / ((2 kg)(85°C - 200°C))
First, let's calculate the difference in temperature:
ΔT = (85°C) - (200°C) = -115°C
Substituting this value into the equation:
c = (90,000 J) / ((2 kg)(-115°C))
Now we can calculate the specific heat of copper:
c = 390.78 J/(kg·°C)
Therefore, the specific heat capacity of copper is approximately 390.78 J/(kg·°C).