Newton’s Laws and the affects of force FORCES Newton’s Laws and the affects of force

Forces Unit: newtons (N) Force is a push or a pull that affect matter. Newton=the force needed to move 1 kg of mass with an acceleration of 1 m/s2

Spring Scale Tool used to measure force on an object. Unit: Newtons (N)

Net Forces Is equal to the number of all forces acting on a single object.

Balanced Forces Are equal forces acting in opposite directions. Produce no change in motion Ex. Tug of war

Unbalanced Forces Produce a change in motion Ex. Kicking a soccer ball, losing tug of war

Centripetal Force A force that pushes or pulls an object in a circular path. Ex. Discus thrower’s arm Video

What path will the discus travel when he lets go? Centripetal Force What path will the discus travel when he lets go? Straight path!

Three Forces on Objects The three forces that act on all moving objects are: 1. Gravity 2. Air resistance (wind) 3. Friction

Gravity pulls a skier downhill Gravitational force The force of attraction that exists between any 2 pieces of matter. Gravity pulls a skier downhill

Universal Law of Gravitation The force of attraction depends on two things: 1. mass 2. distance

Weight versus Mass Which would change when you are on the moon? Weight! gravity changes based on location.

Friction The force that occurs when 2 surfaces rub together and oppose motion.

Types of Friction Static friction- the force needed to put an object in motion Fluid friction- gas or liquid that opposes motion. Sliding friction - sliding an object Rolling friction - adding wheels to an object

Lubricant – a substance that reduces friction. Ex. Oil, water, soap Friction Video