18th May Science, Explode and Implode

Explode and Implode

1. Inside and outside forces acting on the bottle are equal
 -----> normal space
2. Hot- Force acting on the inside is greater than the force acting on the outside 
 -----> Bottle Bulges 
3. Hot water emptied lid on. Cool under cold water. Bottle collapsed. Force acting on outside of bottle is greater than the force acting inside.
Why? 
Air Pressure (a force) is greater air particles have more energy to push "harder" against bottle.  

See Saws

1. If 2 people are equal weight where do they need  to sit on the see saw to balance it? 
They will have to sit in equal distance from the centre
2.  If 1 person is heavier where does this person need to sit balance?
They have to sit close to the centre
Note: Each person's weight is a force pushing down on the see saw.