Frank needs to move a box by sliding it across the floor. Which two factors will most strongly affect how hard Frank needs to push the box?
Choose your answer from:
[1]. The density of the box material and the hardness of the floor.
[2]. The thickness of the box material and the hardness of the floor.
[3]. The total mass of the box and the friction between the box and the floor.
[4]. The total height of the box and the distance between his hands and the floor.
