The image presents three thermodynamics problems. Problem 1 asks for the absolute pressure given a gauge pressure of 5 bar and atmospheric pressure of 1 bar. Problem 2 asks for the heat required to heat 1 kg of water with a specific heat of 4.2 kJ/kg*K by 10 °C. Problem 3 asks about the properties of an adiabatic thermodynamic system.

1. Problem Description

The image presents three thermodynamics problems.

Problem 1 asks for the absolute pressure given a gauge pressure of 5 bar and atmospheric pressure of 1 bar.

Problem 2 asks for the heat required to heat 1 kg of water with a specific heat of 4.2 kJ/kg*K by 10 °C.

Problem 3 asks about the properties of an adiabatic thermodynamic system.

2. Solution Steps

Problem 1:

The absolute pressure is the sum of the gauge pressure and the atmospheric pressure.

$P_{absolute} = P_{gauge} + P_{atmospheric}$

$P_{absolute} = 5 \text{ bar} + 1 \text{ bar} = 6 \text{ bar}$

Problem 2:

The heat required $Q$ is given by the formula:

$Q = m \cdot c \cdot \Delta T$, where $m$ is the mass, $c$ is the specific heat, and $\Delta T$ is the change in temperature.

$Q = 1 \text{ kg} \cdot 4.2 \frac{\text{kJ}}{\text{kg} \cdot \text{K}} \cdot 10 \text{ °C} = 42 \text{ kJ}$

Problem 3:

An adiabatic system is one in which there is no heat exchange with the surroundings. However, mass can be exchanged in some cases.

Therefore, the system cannot either absorb or emit heat.

3. Final Answer

Problem 1: A) 6 bar

Problem 2: Г) 42 kJ

Problem 3: Δ) Δεν μπορεί ούτε να αποδώσει ούτε να απορροφήσει θερμότητα από το περιβάλλον