Water Adhesion by Yang Jiang
3rd Place - Natural Category
School: Jakarta Intercultural School
Teacher: Scott Graham
Water a common thing but also indispensable for every living creature, it is inevitable for the human to interact with water, but have we discover the interactions in detail? One of the cool phenomena between water and human is that water sticks with our skin for a short period when we withdraw our hand from the water. This phenomenon appears because of surface tension and adhesion, which are two common physics phenomena. Water has strong surface tension, and the reason why water has this property is that of cohesion. Cohesion bonds the water molecules on the surface, which creates a layer of connected water. Furthermore, when we put our hand into the water, water will bond with our skin and is called adhesion. With these two physics properties, while the hand withdraws from the water, the water molecules will be carried by the hand, and also the cohesion between water molecules will carry even more water from the hand’s withdrawal. As a result, water will stick with human’s hand for a short period when it is withdrawn from the water.