Question

which of the following is not an example of an open system? * 1 point
a cup of coffee with no lid being spilled.
you riding a bike.
a rope swing with friction between the rope and the branch.
a frictionless roller coaster.

Explanation:

To determine which is not an open system, recall: an open system exchanges matter/energy with its surroundings.

• A cup of coffee (no lid) spills: exchanges matter (coffee) with surroundings (open).
• You riding a bike: you (system) interact with surroundings (air, road) – energy/matter exchange (open).
• Rope swing with friction: friction means energy (heat) is lost to surroundings (open, energy exchange).
• Frictionless roller coaster: in a frictionless, idealized case, no energy/matter exchange with surroundings (closed system, as it's isolated from energy loss due to friction and assumes no matter exchange). So this is not an open system.

Answer:

D. A frictionless roller coaster.