Question

800 J of heat are added to a .3 kg block of glass at a temperature of 300 K. How high will the temperature of the glass rise? The specific heat of glass is 664 J/kg•K.

Answer 1

To determine how high the temperature of the block of glass will rise, we can use the formula for heat transfer:

\[
Q = mc\Delta T
\]

Where:
- \( Q \) is the amount of heat added (in joules),
- \( m \) is the mass of the substance (in kg),
- \( c \) is the specific heat capacity (in J/kg·K),
- \( \Delta T \) is the change in temperature (in K).

Given:
- \( Q = 800 \) J,
- \( m = 0.3 \) kg,
- \( c = 664 \) J/kg·K.

We need to find \( \Delta T \):

1. Rearranging the formula to solve for \( \Delta T \):

\[
\Delta T = \frac{Q}{mc}
\]

2. Substituting in the known values:

\[
\Delta T = \frac{800 \, \text{J}}{0.3 \, \text{kg} \times 664 \, \text{J/kg·K}}
\]

3. Calculating the denominator:

\[
0.3 \, \text{kg} \times 664 \, \text{J/kg·K} = 199.2 \, \text{J/K}
\]

4. Now substitute the result back into the equation for \( \Delta T \):

\[
\Delta T = \frac{800 \, \text{J}}{199.2 \, \text{J/K}} \approx 4.01 \, \text{K}
\]

5. Finally, to find the new temperature of the glass:

\[
\text{Final Temperature} = \text{Initial Temperature} + \Delta T
\]
\[
\text{Final Temperature} = 300 \, \text{K} + 4.01 \, \text{K} \approx 304.01 \, \text{K}
\]

Thus, the temperature of the glass will rise approximately to **304.01 K**.