AP Physics 1: 1.4 Properties of Objects and Systems

be the same thing right Well in order to prevent

him from failing the next physics quiz how should you

respond and hear the potential answers that All right we'll

get started Let's talk inertia way all know what gravity

is and no we're not talking about sandra bullock movie

although it was pretty cool and it did bank has

reconsider our dream of being an astronaut You may have

heard someone say a body at rest tends to stay

at rest and a body in motion tends to stay

in motion The person who first spoke these words was

yes sir isaac newton yet the same old guy who

took an apple to the head and figured out gravity

and he didn't say it exactly like that because they

spoken is funny way back then but that's the gist

of newton's first law of motion what this means is

that if you have a bowling ball sitting on a

table that ball isn't going to just start moving on

its own force needs to be applied to it to

make it move and once it's moving force needs to

be applied to make it stop moving or to make

it change direction that force can be friction or something

that can apply a direct force to stop the motion

So if we know what inertia is We can understand

inertial mass inertial mass is a measure of an object

tendency to resist change is in motion the mohr inertial

mass an object has the more it resists change like

your aunt who still thinks it's nineteen eighty six now

gravitational mass is calculated using an object gravitational weight but

don't confuse mass and weight They're not the same thing

mass doesn't change Sandra bullock has mass no matter where

she is but wait requires gravity that's why sandra can

be weightless in space she's not being pulled down by

the earth's gravitational force or by george clooney to calculate

an object gravitational mass We need to know the objects

weight and the force of gravity So when we put

all this knowledge together we see that the correct answer

is option A inertia refers to an objects resistance to

change while the gravitational mass is the mass calculated from

an object gravitational weight option b is wrong because the

values aren't different and objects inertial mass is the same

as its gravitational mass differences just in how they're measured

see gets it wrong because mass never refers to volumes

plus uses the definition of inertial master To find gravitational

and option d is wrong because the formula used to

calculate the types of masses is the same So if

inertial mass and gravitational masters equal to each other why

do we need to know the diff Well it's Because

they let us describe mass in different ways And that

lets us think about mass in different ways Being able

to think about things in different ways is always helpful

in physics or well any other branch of science and

know our inertial mass doesn't quadruple on those saturday mornings

Just