students learned that objects can exert forces on other objects without touching. which 3 investigations will provide evidence to support what they have learned? a measuring how close a soda can must be before it rolls toward a balloon that has been rubbed on someone's hair b counting the number of staples that are directly attached to a strong magnet c dropping a rubber ball from a distance of 1.5 meters above the classroom floor d placing a magnet against a jar containing a mixture of iron filings and sand e measuring how far a toy car travels across the floor before coming to a stop