Move a can without touching it 1. Place an empty aluminium can on a table so that it can roll freely. 2. Rub an inflated rubber balloon on your hair. 3. Hold the rubbed balloon several centimetres away from the can and move it away from the can slowly. 4. Put the balloon on the opposite side and see if the trick still works. My questions: 1) What makes an object roll? It is obvious that a heavy object cannot roll easily, so, can the mass of an object determine whether it can roll or not? 2) Is the rubbing effect in step 2 still significant for steps 3 & 4? 3) "The aluminium can is an neutral object and the rubber balloon is positively charged after rubbing with hair. Thus, it can attract the aluminium can." Is it what the experiment what to imply? Thanks in advance.