Which object will move faster?

depends on how big the car is and what force is moving them.

Explanation:

the 3lb box will go slower because it is the lightest. the 10lb box is the 2nd slowest. the car will be smaller than the 18 wheeler on the road. but it has less cargo so it will probably go faster. if you are dropping it, then the 18 wheeler will go faster. but if you are seeing if it will go faster on the ground, the car will because it has less cargo or wheels to weigh it down.

explanation:

the masses of the objects and the distance between them

see earlier answer