Final answer:
To show the passage of time in a video, Joel should use a crossfade transition, which is a common method that blends the end of one scene with the start of another.
Step-by-step explanation:
If Joel wants to use a transition in his video to show the passage of time and blend the end of one scene with the beginning of the next, he would most likely use a crossfade. This transition is widely recognized and often used in film and video editing. It creates a smooth visual effect that can subtly suggest the passage of time or a change in location.