17/33
Speed bonus
The specific heat(c) of copper is 0.39 J/g °C. What is the temperature
change(At) when 100 Joules of heat(Q) is added to 20 grams?
24.12°C
351 °C
12.82 °C



Answer :

To calculate the temperature change ([tex]\(\Delta T\)[/tex]) when a certain amount of heat ([tex]\(Q\)[/tex]) is added to a substance, we use the formula:

[tex]\[ \Delta T = \frac{Q}{m \cdot c} \][/tex]

Where:
- [tex]\(Q\)[/tex] is the amount of heat added (in Joules),
- [tex]\(m\)[/tex] is the mass of the substance (in grams),
- [tex]\(c\)[/tex] is the specific heat of the substance (in J/g°C).

Given:
- [tex]\(Q = 100\)[/tex] Joules,
- [tex]\(m = 20\)[/tex] grams,
- [tex]\(c = 0.39\)[/tex] J/g°C.

Let's calculate the temperature change step-by-step:

1. Substitute the given values into the formula:

[tex]\[ \Delta T = \frac{100 \text{ J}}{20 \text{ g} \cdot 0.39 \text{ J/g°C}} \][/tex]

2. Calculate the denominator ([tex]\(m \cdot c\)[/tex]):

[tex]\[ m \cdot c = 20 \text{ g} \cdot 0.39 \text{ J/g°C} = 7.8 \text{ J/°C} \][/tex]

3. Divide the numerator ([tex]\(Q\)[/tex]) by the denominator ([tex]\(m \cdot c\)[/tex]):

[tex]\[ \Delta T = \frac{100 \text{ J}}{7.8 \text{ J/°C}} \approx 12.82 \text{ °C} \][/tex]

Therefore, the temperature change ([tex]\(\Delta T\)[/tex]) when 100 Joules of heat is added to 20 grams of copper is approximately 12.82 °C.

The correct answer is:
12.82 °C