Forces

This week we had a very fun Science lesson which involved us using the swimming pool. We were looking at the forces acting on a water bottle to make it float or sink. 

We found that the more water we put in the bottle, the lower it sank before floating back to the surface. When the bottle is moving downwards, the pull of gravity is the stronger force, and when it is moving back up to the surface, the push of upthrust is the stronger force. 

We found that the bottle only sank when it was completely full with water and no air at all. We also found that if there is just a tiny bit of air in the bottle, the bottle would sit just underneath the surface. We call this neutral buoyancy.