Students were investigating methods of thermal energy transfer by cooking popcorn using four different methods.
image
Which method(s) of cooking popcorn involves the transfer of thermal energy through conduction?
a Only 1
b Both 1 and 4
c Only 2
d Only 4
d Only 4 (since method 4 involves placing the popcorn kernels in direct contact with a hot surface, which is an example of conduction)
In order to determine which method(s) of cooking popcorn involve the transfer of thermal energy through conduction, let's analyze the image and the methods mentioned in the question.
Method 1 involves putting the popcorn in a microwave. Microwaves cook food by emitting electromagnetic waves that generate heat within the food. This process does not rely on conduction, so it is not a method involving conduction.
Method 2 involves using a stovetop pot with a lid. When the pot is placed on the stove, the heat from the burner is transferred to the pot through conduction. As the pot gets hot, it transfers thermal energy to the popcorn, leading to its cooking. Therefore, Method 2 involves the transfer of thermal energy through conduction.
Method 4 involves using an air popper. Air poppers work by blowing hot air onto the popcorn kernels, causing them to pop. This process does not rely on direct contact with a hot surface, like a stovetop pot, so it is not a method involving conduction.
So, the correct answer is:
c) Only 2