Forces, Pressure and Density

4th Form Physics

Formula for Pressure

Force/Area

Formula for Density

Mass/Volume

Formula for Weight

Mass x Gravitational Field Strength

Gravitational Field Strength of Earth

10

Formula for Force

Mass x Accelaration

Newton’s 3rd Law of Motion

If object A exerts a force on object B, then object B must exert an equal and opposite force on object A.

Characteristics of forces in Newton 3 pair

The forces must act on different objects and be the same type to be a Newton 3 pair.

Resultant Force

The total force acting on an object.

Newton’s 1st Law of Motion

An object remains at rest or in constant motion unless a resultant force acts on it.

What type of quantity is Force

Vector Quantity

What type of quantity is Pressure

Scalar Quantity

Volume of a sphere

4/3 x πr³