Question

1. why does steam at 100°c cause more severe burns than liquid water at 100°c? mark only one oval. steam has lower density so it penetrates skin better steam contains additional energy from the latent heat of vaporization steam has a higher temperature than boiling water steam moves faster than liquid water 25. a refrigerator removes heat from its interior and rejects heat to the room. if the refrigerator removes 1000 j from inside and the compressor does 300 j of work, how much heat is rejected to the room? mark only one oval. 1300 j 1000 j 300 j 700 j 26. two materials with the same mass are heated with identical heat sources. material a reaches a higher temperature than material b. what can you conclude about their specific heat capacities? mark only one oval. both materials have the same specific heat capacity material a has a higher specific heat capacity material b has a higher specific heat capacity cannot determine without knowing the fin

Explanation:

Question 24

When water vapor (steam) at \(100^{\circ}C\) condenses on the skin, it releases latent heat of vaporization. This additional energy (compared to liquid water at \(100^{\circ}C\) which just transfers sensible heat) causes more severe burns. Steam and liquid water at \(100^{\circ}C\) have the same temperature. Density and movement speed are not the key factors here.

Step1: Apply the first - law of thermodynamics for a refrigerator

The first - law of thermodynamics for a refrigerator is \(Q_{H}=Q_{C}+W\), where \(Q_{H}\) is the heat rejected to the hot reservoir (room), \(Q_{C}\) is the heat removed from the cold reservoir (inside the refrigerator), and \(W\) is the work done by the compressor.

Step2: Substitute the given values

Given \(Q_{C} = 1000\ J\) and \(W=300\ J\). Substitute into the formula \(Q_{H}=1000 + 300\).

Step1: Use the heat - transfer formula

The heat - transfer formula is \(Q = mc\Delta T\), where \(Q\) is the heat absorbed, \(m\) is the mass, \(c\) is the specific heat capacity, and \(\Delta T\) is the change in temperature. Since \(Q\) (same heat source, same heating time) and \(m\) (same mass) are the same for both materials. We can rewrite the formula as \(c=\frac{Q}{m\Delta T}\).

Step2: Compare the specific heat capacities

If \(T_{A}>T_{B}\) (assuming initial temperatures are the same, \(\Delta T_{A}>\Delta T_{B}\)), then \(c_{A}=\frac{Q}{m\Delta T_{A}}\) and \(c_{B}=\frac{Q}{m\Delta T_{B}}\). Since \(\Delta T_{A}>\Delta T_{B}\), \(c_{A}

Answer:

Steam contains additional energy from the latent heat of vaporization

Question 25