physics chapter 3 force and pressure

Types of forces

contact forces (4)

non-contact forces (3)

Mass and weight

differences between mass and weight (5)

** gravitational force acting on object with mass

mass:

it does not change with the location, shape and speed of the body (for speed less than light)

** can also use weighing scale to measure weight

Gravitational field

Must memorise: gravitational field is a region i which a mass experiences a force due to gravitational attraction

gravitational field strength

** W=mg * memorise definition

common weiging instruments

** difference between what it measures and what it is used to find

Measurement of mass

density and mass

density = mass/volume

if the object has the same density as its surrounding medium (eg water), the object will be in the centre

Pressure

** BE careful of units → SI units

relationship between pressure, force and area

pressure explain template

1. The object has a smaller/larger contact area

2. Since pressure=force/area, the pressure exerted wil be larger/smaller for the same force applied