1.1 forces intro
TRANSCRIPT
What is a Force?
• Anything that can change an objects motion (direction and/or speed) or shape.• A push, pull, or twist!
Forces on an object
• Objects will always have some sort of force acting on them. • They only change movement or change
shape if the forces are UNBALANCED. If the forces are BALANCED, the object will just keep doing what it’s doing. • This includes travelling at a constant
velocity
Balanced or Unbalanced?A car travelling at a constant speedA car speeding upA book sitting on a shelfA bike slowing downAn apple falling from a treeA can being crushedA shopping cart being pushed
Constant velocity? Changing velocity?
Balanced or Unbalanced?A car travelling at a constant speed BalancedA car speeding up UnbalancedA book sitting on a shelf BalancedA bike slowing down UnbalancedAn apple falling from a tree UnbalancedA can being crushed UnbalancedA shopping cart being pushed
Constant velocity? Balanced Changing velocity? Unbalanced
Contact and Non-Contact ForcesContact Forces
A force that acts when an object makes contact with another object (touching).e.g. - Pedalling a bike, sliding a book of a desk in rage, or jumping in the air
Non-Contact ForceA force that acts on an object without contact being madee.g. - Gravity pushing/pulling us down to Earth, magnets on the fridge, electrostatic forces holding up hair.
Contact or Non-ContactAn apple flailing from a treeA car speeding upMag-lev trains being held upA bike slowing downA hover-board (a real one)A can being crushedA space shuttle launch
Upward Force? Downward Force?
Contact or Non-ContactAn apple flailing from a tree Non-ContactA car speeding up ContactMag-lev trains being held up Non-ContactA bike slowing down ContactA hover-board (a real one) Non-ContactA can being crushed ContactA space shuttle launch
Upward Force? Contact Downward Force? Non-Contact
All done!An activity:
http://www.bbc.co.uk/bitesize/ks3/science/energy_electricity_forces/forces/activity/
And another (if there’s time):
http://kerala.skoool.in/content/KS3%20LOs/physics/forces/