Physics ~ Forces

*Force/ velocity/acceleration/ momentum are vector quantities: magnitude and
direction
~ *Can be shown by arrows; direction of arrow shows vector and size shows scalar. <—[] []—>
( The ‘[]’ are moving at the same speed in both directions but have different velocities as they are going different ways)

*Speed/ distance/ mass/ temperature/ time are scalar quantities: magnitude and NO direction

• Contact forces are when two objects are touching, like friction/ air resistance/ tension in ropes
• Non contact forces do not need two things to be touching, like gravitational/ magnetic/ elastic forces

Gravity gives things weight
Weight is the force acting on an object due to gravity

Mass is the amount of something in an object- small value anywhere in the universe

Gravitational field strength (GFS) is stronger with heavier objects and closer to the mass causing the field.
Weight depends on GFS where the object is
an objects mass on earth and moon is equal but weight will be less on moon
Weight acts from the centre of mass (where assumed mass is all concentrated) but in uniform objects (same density…