Question 7
A metal pot with hot soup in it is placed on a cool stone countertop, as shown in the diagram below.
The numbered arrows show the transfer of heat from the pot of soup to the surrounding environment. Which list correctly identifies each method of heat transfer?
a
1 — conduction; 2 — convection; 3 — radiation
b
1 — radiation; 2 — radiation; 3 — convection
c
1 — convection; 2 — conduction; 3 — radiation
d
1 — convection; 2 — conduction; 3 — conduction
c) 1 - convection; 2 - conduction; 3 - radiation
Well, it looks like this pot of soup is getting around! Let's analyze the options one by one:
a) 1 - conduction; 2 - convection; 3 - radiation
Hmm, it seems like this option might be playing a little hot and cold with us. Conduction is the transfer of heat through direct contact, but in this case, the soup is not touching the countertop directly. So, let's simmer this option a bit longer.
b) 1 - radiation; 2 - radiation; 3 - convection
Oh dear, it seems like we have a real case of double radiation here. While radiation does occur in this situation, there are other methods of heat transfer happening as well. Looks like this option is trying to heat things up, but it's not the right answer.
c) 1 - convection; 2 - conduction; 3 - radiation
Ah, this option seems to have the right mix of ingredients! Convection occurs when heat is transferred through the movement of a fluid, in this case, the air surrounding the pot. Conduction happens when heat is transferred through direct contact, like the pot touching the countertop. And radiation is the transfer of heat through electromagnetic waves. Looks like we have a winner here!
d) 1 - convection; 2 - conduction; 3 - conduction
Well, it seems like this option wants to double up on conduction. While conduction does happen between the pot and the countertop, there are also other methods of heat transfer at play. Looks like this option needs to cool down a little.
So, the answer to this question is option c: 1 - convection; 2 - conduction; 3 - radiation. Keep up the good work, and remember, never underestimate the power of a hot pot of soup on a cool countertop!
The correct answer is:
a) 1 - conduction; 2 - convection; 3 - radiation
To identify the correct list that identifies each method of heat transfer, let's understand the three methods of heat transfer first:
1. Conduction: Conduction is the transfer of heat through direct contact between objects. When two objects at different temperatures touch each other, heat will flow from the hotter object to the cooler one.
2. Convection: Convection is the transfer of heat through the movement of a fluid (liquid or gas). As the fluid is heated, it becomes less dense and rises, while the cooler fluid sinks. This creates a circulating flow that transfers heat.
3. Radiation: Radiation is the transfer of heat through electromagnetic waves, which can travel through empty space. This is how the heat from the Sun reaches Earth, for example.
Considering the diagram provided, we can see that the pot of hot soup is in direct contact with the cool stone countertop. Hence, heat is transferred directly from the pot to the countertop through conduction. Therefore, we can eliminate options b and d, which both include radiation as one of the methods.
Next, we observe that the hot soup transfers heat to the surrounding environment through the air. Air is a fluid, and when it is heated, it rises and cooler air replaces it, creating convection. This rules out option a, which does not include convection.
Hence, the correct list that identifies each method of heat transfer in this scenario is:
c) 1 — convection; 2 — conduction; 3 — radiation