Physics Newton's Laws thru Atwood Machines

Newton's 1st Law of Motion

An object at rest will stay at rest, amd an object in motion will stay in motion, at contant velocity and in a straight line, unless acted upon by a net force

Force

A push or pull on an object, measured in Newtons

Net force

The vector sum of all the forces acting on an object, if the forces are balanced there is no

Inertia

The tendency of an object to resist a change in velocity, is basically synonymous with mass

Free body diagram

Draw object as dot as origin of two axes, draw forces acting on object as vectors

Normal Force

Force coming perpendicularly out of a surface upon which an object is pressed

Newton's 2nd Law of Motion

The acceleration of an object is in the direction of and directly proportional to the net force applied, and inversely proportional to the object's mass

Fnet = ma

Newton's 2nd Law of Motion equation net force

mg =Fg

Equation for weight

Newtons

Unit for weight

Newton's 3rd Law of Motion

All forces come in pairs. If Object 1 exerts a force on Object 2, then Object 2 must exert a force back on Object 1 that is equal in magnitude and opposite in direction

For every action there is an equal and opposite reaction

Newton's 3rd Law of Motion

Friction

Force that opposes motion, its magnitude is determined by the nature of the surfaces and the normal force, kinetic is less than static

mgy = mgscosø

Y component of mg in incline problems

Atwood machine

Experimental device in which 2 object's of masses m1 and m2 are connected by a massless string over a massless pulley, pulley is frictionless, tension on string is constant

a = g (m1 - m2)/(m1 + m2)

Equation for acceleration in Atwood Machine problems

mgx = mg sinø

x component of mg in ramp problem down the ramp

3.26 m/s2

An Ideal pulley has a 4kg block resting on a frictionless table attached to a 2 kg block. What will the acceleration of the two block be when released?

3.26 m/s2

If the larger mass of 10 kg is released what will the acceleration of the masses be if the lighter mass is 5kg?

ideal string

String that has no mass can only pull and does not streatch

ideal pulley

Frictionless pulley

mgsinθ

The Fnet down the incline

m1gm-m2gsinθ / m1 +m2

Equationn acceleration for an incline atwood machine

Normal force times coeffieient of kinetic friciton

Equation for kinetic friction

normal force

force opposite of the weight and perpendicular. to the surface

static friction

the force that resists the initiation of sliding motion between two surfaces that are in contact and at rest

kinetic friction

Friction between moving surfaces