Four boxes of various masses are placed on a friction free table. Rank these boxes according to net force by listing them in order from greatest to least.

A) <-5N--| 5 kg |--10N-> B) <-10N--|10kg|-15N--> C) <-10N--|5kg|-15N--> D) <-5N--|20kg|-15N-->

 

Answer

If the friction-free table is horizontally level: D (with net force of 10 Newtons) then B, C, A (with net force of 5 Newtons) are all equal. The mass of the object does NOT matter since the object's weight is countered by the Normal Force. ======================================… However, IF the friction-free table is inclined, say 45 degrees .... I think it will still be D, B-C-A but the net force will be different. ======================================… IF there is friction AND the table is inclined, the object's mass will matter ... because mass determines weight which determines Normal Force which determines Force of Friction.