Read the passage about Evan.
Evan has a black car, and it gets very hot inside the car on a hot summer day. Evan wants to cool his car down as quickly as possible so he can be cool on his drive home from school.
How could Evan position his air conditioner vents to best cool down his car?
A
up because convection causes cold air to sink and hot air to rise
B
up because conduction causes cold air to sink and hot air to rise
C
down because convection causes cold air to rise and hot air to sink
D
down because conduction causes cold air to rise and hot air to sink
A. up because convection causes cold air to sink and hot air to rise
C
down because convection causes cold air to rise and hot air to sink
In order to determine how Evan could position his air conditioner vents to best cool down his car, we need to understand the principles of convection and conduction. Convection is the process by which heat is transferred through the movement of fluids (in this case, air). Conduction, on the other hand, is the transfer of heat through direct contact between objects.
Based on these principles, we can eliminate options B and D, as they incorrectly state that cold air sinks and hot air rises due to conduction. This is not accurate. In fact, conduction does not affect the movement of air in terms of hot air rising or cold air sinking.
Now, let's analyze the remaining options. Option A suggests positioning the air conditioner vents up because convection causes cold air to sink and hot air to rise. While it is true that hot air naturally rises, in this scenario, Evan wants to cool down his car as quickly as possible. Positioning the vents up is not the most effective choice to achieve this, as it would work against convection by allowing cold air to sink, potentially delaying the cooling process.
Thus, the most appropriate choice is option C, which recommends positioning the air conditioner vents down because convection causes cold air to rise and hot air to sink. By directing the air conditioner vents downwards, Evan can manipulate the convection process to effectively push the cold air upwards and cause the hot air to sink, resulting in a faster cooldown of the car's interior temperature.