What are the answers to questions 8, 9, 10, and 11?

$$Q_{\text{Joules}} = Q_{\text{calories}} \times \text{conversion factor}$$ $$Q_{\text{Joules}} = 12000 \text{ cal} \times 4.184 \frac{\text{J}}{\text{cal}}$$ $$Q_{\text{Joules}} = 50208 \text{ J}$$

The correct option is D. 50,208J.

10. Some water is heated in a pot. The major mode(s) of heat transfer within the water is/are

When water is heated in a pot, the water at the bottom heats up, becomes less dense, and rises. Cooler, denser water from the top sinks to take its place, gets heated, and rises. This continuous circulation of fluid is the primary way heat is transferred within the water.

The correct option is A. convection.

11. Calculate the quantity of heat required to completely convert 20g of ice at 0°C to water at the same temperature. (L_f = 336J/g)

To calculate the heat required for a phase change (melting ice to water) at a constant temperature, use the formula:

$$Q = mL_f$$

where $Q$ is the heat energy, $m$ is the mass, and $L_f$ is the specific latent heat of fusion.

$$m = 20 \text{ g}$$ $$L_f = 336 \frac{\text{J}}{\text{g}}$$

$$Q = (20 \text{ g}) \times \left(336 \frac{\text{J}}{\text{g}}\right)$$ $$Q = 6720 \text{ J}$$

$$Q = \frac{6720 \text{ J}}{1000 \frac{\text{J}}{\text{kJ}}}$$ $$Q = 6.72 \text{ kJ}$$

The closest option is D. 6.7KJ.