A truck driver has a truckload of chickens (in a nearly sealed truck) which exceeds the maximum weight allowance. The driver's idea to trick the scale at a weigh station is to fill any empty space with helium balloons. Will this plan work?

A) Yes, the measured weight will decrease significantly.

B) Yes, the measured weight will decrease slightly.

C) No, there will not be a measurable difference.

Solution: B. The helium balloons have smaller mass than an equal volume of normal air. The true weight of the truck and contents has decreased, so the normal force (measured weight) of the truck will decrease.