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Playlist AP® Physics 1: Object Interaction and Forces 13 videos

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AP Physics 1: 1.1 Object Interaction and Forces
258 Views

If there's one good thing about the heat death of the universe, it's that we'll all have an excellent excuse for dodging physics homework.

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AP Physics 1: 1.2 Object Interaction and Forces
213 Views

The real moral of the story here is just "don't get in the way of elephants or tigers." That is not the kind of kinetic energy you want to absorb.

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AP Physics 1: 1.3 Object Interaction and Forces
236 Views

Hi there. We'd like to wave hello to you, but the internet isn't letting us. So instead, accept this fun question about waves and physics! It's alm...

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AP Physics 1: 3.3 Object Interaction and Forces 174 Views


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AP Physics 1: 3.3 Object Interaction and Forces. What is the minimum acceleration needed for the box to remain attached to the van?

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Transcript

00:00

Thank you We sneak and here's your shmoop du jour

00:05

brought to you by vans which just aren't as groovy

00:08

as they used to be Check the falling image and

00:12

passage Nice hair glasses in your stuff All right What

00:20

is the minimum acceleration that aunt gertrude would have to

00:23

maintain in order for the box to remain attached to

00:26

the van and hear the potential answers all about friction

00:30

Uh no There's A lot going on in this question

00:33

Well let's try to make it simpler on ourselves by

00:35

drawn up the little force diagram right here Okay we've

00:40

got one force the van going in the ex direction

00:43

And this question will label that in for normal force

00:47

to calculate that force we use our trusty formula force

00:50

equals mass times acceleration Then we have to force is

00:53

in the y direction there's gravity pulling down on the

00:56

box and friction pushing it up In order for the

00:59

box to not fall these two forces have to balance

01:02

each other out So the force along the y axis

01:05

is equal to mass times gravity plus friction Well because

01:09

the forces air acting in different directions the first part

01:12

of the equation mass times gravity will be expressed as

01:16

a negative number and here's the equation All right Well

01:19

now let's deal with the friction in our scenario here

01:22

The normal force in is pushing back Against the box

01:25

the normal force and the coefficient of friction together create

01:28

the friction force Here The equation is friction is less

01:32

than or equal to the coefficient of friction times the

01:36

normal force in the equation musa bass represents the coefficient

01:41

of static friction it's important to remember that the question

01:45

is asking us to find the minimum acceleration needed to

01:48

hold the box in place If the normal force is

01:51

too small the friction force won't be strong enough to

01:53

balance out gravity in the box and fall But if

01:56

gertrud floors it jacking the normal force way up a

02:00

friction force will reduce that's because the normal course would

02:03

be pushing on the box so hard that the friction

02:05

force wouldn't have to be doing this much That's why

02:08

the equation has a lesser than or equal to sign

02:11

since we need to find the minimum force needed for

02:14

gertrude to make this crazy scheme work that means that

02:17

friction force needs to be at its highest possible point

02:20

Thor equation for four should really have an equal sign

02:24

okay quick reminder We're trying to balance the forces in

02:27

the uae direction the equation to use is force equals

02:31

the product of negative mass and gravity plus the product

02:35

of the coefficient of friction and the normal force And

02:38

normal force equals mass times acceleration Lastly the result of

02:43

our equation is zero because the forces balance each other

02:46

out right When we simplify the equation and solve for

02:50

acceleration we see that acceleration equals gravity divided by the

02:54

coefficient of friction for ten meters per second squared divided

02:58

by zero point six which comes out to about sixteen

03:02

point seven meters per second squared making option D The

03:06

correct answer And we're thinking of trading in our van 00:03:09.02 --> [endTime] for something easier to parallel park

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