Spin a tone generator (e.g. phone with app) around your head so that students can hear the frequency rising and falling due to the Doppler effect.
Science content (2016 curriculum):
Physics: Light and Sound (1)
Physics: Energy forms, Conservation of Energy (1, 3, 4, 5)
Earth/Space: Sun, Moon, Solar System, Universe (1, 4, 6)
Earth/Space: Extreme Environments, Space Exploration (6)