Final answer:
The subject of this question is Physics. It involves the study of matter, energy, and their interactions to explain the behavior of objects.
Step-by-step explanation:
The subject of this question is Physics. Physics is the branch of science that deals with the study of matter and energy and their interactions. It explains the behavior of objects and the forces acting upon them. In this question, the concept of coasting on a slippery surface can be explained using principles of physics, such as friction and motion.