Ahorizontal force of 15n is needed to keep a box sliding on a horizontal floor at a constant speed of 0.5m/s. the speed of the box is increased to 1.5m/s by some means (which is not the concern of this question). what horizontal force would be needed to keep the same box sliding on the same horizontal floor at a constant speed of 1.5m/s? group of answer choices a constant horizontal force of 15 n a constant horizontal force of 45 n a horizontal force that gradually decreases from 15 n to 5 n. a horizontal force that gradually increases from 15 n to 45 n. a constant horizontal force of 5 n