Read the paragraph.

Students enrolled in Physics 101 were asked to assemble wooden cars to demonstrate the principles of friction. The cars began as uniform kits, each containing a four-inch block of wood, four wheels, and two metal rods. Students carved, assembled, painted, and embellished their creations. In the end, there was an impressive line-up of mini racers with sleek, sanded bodies. They represented every color of the rainbow, with racing stripes and lightning bolts adorning many.

What is the purpose of the details in the paragraph?

to develop the central idea of the principles of friction
to establish the importance of learning higher-level science
to describe students’ cars to help readers visualize them
to explain the importance of the students’ creations