The longer the straw, the more difficult it is for you to suck up the drink. The best mechanical pumps can only manage 10m. Instead, trees use a method called osmosis to force water upwards. Osmosis works because there is a difference between the sap, or juice, inside the roots and the water in the ground outside. Sap contains large amounts of sugary substances.
Ground water contains only tiny amounts of dissolved nutrients.
We say that sap is more concentrated than the ground water. 1- You will need a large, smooth potato about 10cm long and 6cm across. Carefully peel the potato using a chopping board to protect your work surface. 2 - Cut the peeled potato in half and then slice off the rounded ends. You will now have two round potato slices.