Physics

Force

Success Criteria

Forces

The earth pulls you down

When you dive in the pool or ocean, the water pushes against your skin

When you drive fast, the car seat pushes into your back

Your enemy may push you to the ground, but your friend will pull you back up to your feet

If your walk you dog, and he is strong and fast, like Luka, then you will be pulled along

A truck pulls a trailer

A bulldozer pushes the soil

A digger pushes its bucket. When the bucket is tipped, the earths gravity pulls the soil to the ground

So Forces push or they pull.

A Force is a Push or a Pull


Force

Forces are a push or a pull

Forces cause things to move.

When a Force is applied to a thing it might

  1. Change direction

  2. Change velocity

  3. Change shape

Force can only cause movement if it is unbalanced

A Balanced force is like you leaning on a wall

A Unbalanced force is like the Hulk leaning on a wall and it tips over

Movement will only happen if the Force is Unbalanced

Balanced Forces = like tug of war and there is no movement

Unbalanced = tug of war and one side wins

Force in Newtons

The unit for Force is named after the person that dedicated his life to the study and exploration of physics - Newton

Contact vs Non Contact Forces

Although a force is a push or a pull. The force doesn't need to be touching!

When you push on a toy truck to move it - this is contact - so its a contact force

When you use a magnet to push the truck around you are not touching the truck, this is non-contact

Contact forces are whenever two things are touching. This includes

  1. Friction

  2. Air friction and water friction - Drag

  3. Tension - springs, rope, rubber band, slingshot

  4. Support or Normal force (the force of the ground)

  5. Thrust

  6. Buoyancy (in air or water)

Non-contact forces are forces that don't touch. This includes

  1. Magnets

  2. Electrostatic force - this is what causes your hair to raise up with a balloon

  3. Gravity

Watch this GCSE Physics clip, it is really good!

Friction Force


Force Vectors

Force = Mass x Acceleration


Newtons laws