Forces 1 Flashcards
Scalar and vector quantities, Contact and non-contact forces, Gravity, Resultant forces, Vector diagrams.
Newton’s third law
‘Every action has an equal and opposite reaction’…
which means that whenever two objects interact, they exert equal and opposite forces on each other.
Give an example that shows ‘every action has an equal and opposite reaction’
A satellite in Earth orbit:
There are non-contact gravitational forces between Earth and the satellite.
The Earth pulls the satellite.
The satellite pulls Earth.
These forces are equal in size and opposite in direction.
Why does it hurt when you kick a door hard?
The door exerts an equal and opposite force on your foot, which causes it to hurt.
Newton’s first law
An object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force (resultant force).
