7 How much thermal energy is needed to raise the
temperature by 10°C of 5 kg of a substance of
specific heat capacity 300 J/(kg °C)?
How less

es
8



Answer :

To solve this problem, you can use the equation that relates the thermal energy (Q) needed to raise the temperature of a certain mass of a substance by a specific number of degrees Celsius. The equation is: \[ Q = mc\Delta T \] where: - \( Q \) is the thermal energy in joules (J), - \( m \) is the mass of the substance in kilograms (kg), - \( c \) is the specific heat capacity in joules per kilogram per degree Celsius \( \left( \frac{J}{kg \cdot °C} \right) \), - \( \Delta T \) is the change in temperature in degrees Celsius (°C). Now, let's apply the given values to the formula: - The mass \( m \) of the substance is 5 kg, - The specific heat capacity \( c \) is 300 \( \frac{J}{kg \cdot °C} \), - The temperature change \( \Delta T \) is 10°C. Plugging in these values, we get: \[ Q = (5 \, kg) \times (300 \, \frac{J}{kg \cdot °C}) \times (10 \, °C) \] Multiplying these values together, we find the thermal energy \( Q \): \[ Q = 5 \times 300 \times 10 \] \[ Q = 1500 \times 10 \] \[ Q = 15000 \, J \] Therefore, the amount of thermal energy needed to raise the temperature by 10°C of 5 kg of a substance with a specific heat capacity of 300 J/(kg °C) is 15,000 joules.