Dynamics

Force (definition)

Force (definition)

push or pull on an object

What does force cause

change shape/size, start/stop, accelerate/decelerate

Measuring forces

-Spring balance

-Newtons (N)

Mass

How much matter an object contains, which is constant

Weight

Force exerted an a mass by gravity, which is not constant

Resultant force

Total amount of force acting on an object

Motion

caused by unbalanced force

Equilibrium

Forces that are in balance, are static/dynamic

Newton’s first law

A body stays in rest, or if moving it continues to move with uniform velocity unless an external force makes it behave differently

Inertia

tendency of a body to remain unchanged

The larger the mass, the … the interia

greater

What measures inertia?

mass of a body

Newtons second law

F=ma

F has to be in …

N (Newtons)

m has to be in …

kg

a has to be in …

m/s^2

Newtons third law

For every action there is an equal and opposite reaction

Terminal velocity

-Object falling

-Gains speed as falling

-Air resistance is opposing falling motion

-As object moves faster, it experiences more air resistance

-Air resistance balances weight

-Forces are in balance

Friction positives

-braking cars/bikes

-Walking

-Writing

-Asteroids burn

Friction negative

-Produces heat, lost energy

-Opposes motion

-Forest fires

-Money/effort into techniques to stop friction (greasing, oil)

types of forces

-gravitational

-friction

-Normal

-Electric

-Magnetic

-Nuclear strong

-Nuclear weak

-Air resistance

Electric force

push or pull anything with charge

Nuclear strong force

Keeps nucleus inside atoms

Nuclear weak force

Unstable subatomic particles

Net force

sum of all forces acting on an object

impulse formula

Ft = Mv - Mu