1- suppose your friend is sitting on a sled and asks you to move her across a flat, horizontal field. you have a choice of (a) pushing her form behind by applying a force downward on her shoulders at 30° below the horizontal, or (b) attaching a rope to the front of the sled and pulling with a force at 30° above the horizontal . which option would be easier? why?
2- a crate is sitting in the center of a flatbed truck. as the truck accelerates to the east, the crate moves with it, not sliding on the bed of the truck. what force is accelerating the crate? in what direction is this force?
3- which one you prefer; winning 2.0 newton of gold on earth or 1.0 newton of gold on the moon?