Copyright and Fair Use

“A student wants to use a 20-second clip from a popular song in a video they are creating for a school project. The video will be shown only to their class and teacher. Explain whether this use is likely fair use, and why or why not. A student creates a parody of a famous movie poster for a presentation in their English class. The parody significantly alters the original poster for comedic effect and commentary. The student credits the original poster. Is this use likely fair use, and why or why not?”