interaction through the application of the forces (chapter 14)

type of forces

contact forces

non-contact force

there is contact force whenever an object touches something

examples for contact force: friction ( two force rubbing against on another)

a force that acts on an object without touching it

examples of non-contact forces:

electrostatic force : we can feel it when we use a transparent sheet of plastic to wrap a book

magnetic force: it is the force exerted nu a magnet on magnetic materials such as iron and steel

gravitational force: a force that attracts object to planet

measuring force

instruments for measuring

extension spring balance

compression spring balance

mass and weight

weight

mass

a measure of the amount of matter in a body
SI unit: kilogram (KG)

instrument used is:
beam balance
electronic balance

a measure of the gravitational force acting on an object
SI unit: newtons (N)

dependent on the location's gravitational field strength as give by this formula: weight = m x gfs

gravitational force IS NOT gravitational field strength

the mass of an object on earth will remain the same if on the moon

the weight of an object will change if on moon

instrument used: extension spring balance

speed

formula: speed = distant (m)/time (s)

effects of force

turning effects of forces

pressure

turning effects of forces is also known as moment or torque

when the perpendicular distance is the largest, the turning effect is the greatest

turning effect of forces is being applied when opening, using a crowbar and using a wheelbarrow

it is the amount of force acting perpendicular on a unit area

formula: force/area

to increase pressure, increase applied force and decrease contact area