(4)The tube is made to be at the bottom of the beaker by pulling the string and the end of the string is tied to the side of the beaker; a scale reading is made(same as above). The results from investigations 3 and 4 should be equivalent to those in[5].(5) The tube remains at the bottom but now the string is tied to astand outside the beaker-tube-balance system: the reading is checked (heavier than all of the above). This latter set-up is to show the effect of the external force.