A Body at Rest in Shanghai.
More specifically, the centre of mass of a body remains at rest, or continues to move in a straight line.
When I’m cycling and I notice a piece of glass or a large stone directly in my path, I may not have time to change my direction of motion. But I can quickly shift my bike to the left, while shifting my body to the right. My tires will avert disaster, while my centre of mass has not changed.
The same works in skiing. You’ve probably seen downhill (slalom) events wherein a skier quickly shifts her skis right, her body left, to get her skis around the gate while minimizing the change in her centre of mass and direction of travel.
