dynamics

Y'all... eish

What is Newton’s First Law

A body continues in its state of rest, or with uniform velocity, unless acted on by a resultant force

what does it mean when the resultant force is zero

at rest or constant velocity in a straight line

what happens when a resultant force is acting on an object

object accelerating or decelerating

what forces act on an object when it is at rest

Normal contact force and gravity

what forces act on an object when in constant velocity in a straight line

thrust and resistive

what direction do forces act when an object accelerates

same direction

what direction do forces act when an object decelerating

opposite directions

what is Newton’s Second Law

for a body of constant mass, its acceleration is directly proportional to the resultant force applied to it.

define force

rate of change in momentum

what equation do you use for Newton’s Second Law

F = ma

what is a free body diagram

graphical illustration used to visualize the applied forces, moments, and subsequent reactions on a body in a given condition

what is mgsine()

horizontal weight component

what is N

Normal contact force

what is f

friction

what is Mg

weight

what is mgcos()

vertical weight component

what is the name of this diagram

free body diagram

what is Newton’s Third Law

when two bodies interact, one body exerts a force on the second body and the second one exerts an equal and opposite force on the first one

in Newton’s Third Law, where are the action-reaction forces

on opposite bodies

what is an example of Newton’s first law

a bowl set down on a table

what is an example of Newton’s second law

a parachute being open

what is an example of Newton’s third law

moon orbiting planet

what is the acceleration of connected objects when a force is exerted on them

the same

what is combined effect of several forces

resultant force

what is the SI unit of force

Newton

what can forces do to objects

change shape or dimensions of objects

what kind of quantity is force

vector

why are spring balances called Newton balances

because that is the SI unit of force

what different changes can a force apply to an object

tension, squeezing, pulling, stretching, squishing

what fact should you keep in mind when measuring forces

the fact forces can change the dimensions of objects in a reproducible way

what does changing object dimensions in a reproducible way mean

under the same conditions so that the changes can be measured and replicated reliably

what did Aristotle discover

natural state of object was at rest and is necessary to make it move

who believed in the greater the force, greater the speed

Aristotle

what did Galileo question statement to Aristotle be

motion at constant speed can be as natural as a state of rest

what can make the friction on motion significantly less

pushing an object on a smooth, lubricated surface can make it vanishingly small

what does the force of friction do

oppose pushing force

how many laws does Isaac Newton have

three

what is the formula for force

force equals mass time acceleration

what is 1 Newton defined as

force which will give you a 1kg mass and acceleration of 1ms^-2

what is inertia

what is the property of an object to stay with no resultant force

what quantity is momentum

vector

define momentum

the product of its mass and its velocity

how do you calculate momentum

mass x velocity

what is the unit of momentum

N s

what is the base quantity of momentum

Kg m s^-1

what is momentum when an object is at rest or velocity is uniform

momentum is zero

what is resultant force in terms of momentum

rate of change of its momentum

what is momentum when provided the external resultant force is zero

momentum is constant

what is Newton’s second law of motion in terms of momentum

the resultant force acting on an object is proportional to the rate of change of its momentum

what is Newton’s second law in terms of the constant of proportionality

the resultant force acting on an object is equal of the rate of change of momentum

what is momentum expressed in symbols

F = Δp/Δt

what is momentum expressed in symbols for constant mass

F = Δ(mv)/Δt = m(Δv/Δt) = ma

what is weight

force of gravity which acts on an object

what is the unit for weight

N

why do you never specify the direction of force of gravity even though it goes in the same direction?

always going towards center of Earth

what do newton balances find

weight

why is a balance in a lab called a balance

to represent balance of forces

what is weight equal to on a balance found in a lab

to previous calibration to balance

why do objects at rest have weight

gravity is always acting

what makes an object at rest have zero resultant

normal contact force

what does “normal” in normal contact force mean

acts perpendicularly to plane of contact

what does “contact“ mean in normal contact force

happens because of contact between object and surface plane

what kind of balance is used to compare weight

lever balance

what type of balance is this

top pan balance

what type of balance is this

level balance

what kind of balance is this

sprig balance

what other body exerts a force on an object at rest other than normal contact force (think of a book and a table)

upward force exerted by the table on the book

what is the principle of conservation of momentum

the total linear momentum of a system of a system of colliding bodies with no external forces acting, remaining constant

what is the meaning of a closed system

matter cannot enter or leave, but energy can flow across the boundaries

what is an isolated system

where both matter AND energy are prevented from entering or leaving the system

what does this represent

isolated energy system

what does this represent

closed energy system

what is the protionality of mass and velocity in momentum

directily proportional

what direction does momentum and velocity work in

same direction

define impulse

product of force acting on an object and the time during which the force acts

symbol for impulse

J

formula for impulse

J = F t

what is the unit for impulse

N s

what quantity is impulse

vector

what happens to the momentum of two colliding bodies hittign each other at the same time

one loses and one gains

what is the firmula for total initial momentum = total final momentum

Mu_x + Mu_x = Mv_y + Mv_y

if no kinetic energy is lost during collisiton, what is said about it

it is perfectly elastic

formula for elastic collision

u _x- u_y = v_x - v_y

what happens when two object collide and no energy is lost

converted to other forms

what happens when pulling force is greater than friction force

object accelerates

what happenes when pulling force is equal to friction force

object is at constant velocity

what happens when pulling force is less thant fricition force

object is decelerating

where does viscouse force happen

in fluids

is water high or low viscosity

low

is glue high or low viscosity

high

what is terminal velocity

maximum constant speed an object reaches when falling through a fluid

what is resultant force downward in viscous fluid

weight - viscous force

what is non-unifrom motion

when acceleration is initially gravity but decreases to zero with time

what is upthrust or bouyancy dependent on

fluid density

what is resultant force downward when talking about buoyancy

weight - (upthrust + visvous force)

how is resultant force during terminal velocity with upthrust / buoyancy

weight = upthrust + viscous force