AP Physics 2: 2.3 Object Interaction and Forces

AP Physics 2: 2.3 Object Interaction and Forces. What is the net force in this situation?

AP Physics 2Object Interaction and Forces
LanguageEnglish Language
Science Practice 2Using math appropriately

Transcript

00:17

tug of war over They didn't pay attention in physics

00:20

Instead of dispersing themselves equally they distributed themselves as in

00:25

the diagram scene right chair with one person on either

00:28

side And one person in between The person on the

00:31

left pulls with a force of nine Newton's The person

00:34

on the right pulls with a force of twelve noons

00:36

and the person this guy right here on top pulls

00:38

with a force of four news what's the net force

00:42

in this situation and here the potential answer sounds like

00:47

a movie star Cary grant Okay well this will be

00:50

quite the interesting tug a war match Let's Just hope

00:53

no one gets hurt Is there drag along the ground

00:55

but looking at the set up here we know we're

00:57

dealing with vectors And to find the total sum of

01:00

vector forces we can add them up Yeah once your

01:04

vector Victor All right Well let's think of this three

01:07

headed monster as if it was on a coordinate plane

01:10

A different kind of plain The middle point will be

01:13

zero for both axes The first time pulling toward the

01:16

left will be a point negative nine zero And the

01:19

person pulling toward the right will be a point Twelve

01:22

zero The guy pulling up one The one who doesn't

01:25

understand how war works and is really messing up the

01:28

whole shebang Yeah well he'll have y coordinate of zero

01:31

comma four right there Now we can add the x

01:33

and y components Tto find the net force Well the

01:36

net force along the x axis equals negative nine plus

01:39

twelve plus zero And along the y axis it equals

01:43

zero plus zero plus four So that gives us a

01:46

net force along the x axis of three And along

01:48

the y axis of four Now because these forces are

01:52

in a right angle to each other we can use

01:54

the pythagorean theorem toe Add them together Little pythagoras taught

01:58

the world that a squared plus b squared equals c

02:02

squared that we can plug in our numbers and find

02:05

that the net force Vector is five and while we

02:08

don't have the exact direction we know that the forces

02:11

are being applied to the north and to the east

02:15

Well in our coordinate playing the force will be in

02:17

the upper right quadrant All of this tells us that

02:20

the answer is c right there five in northeast when

02:24

we're dealing with vector edition diagrams are always helpful so

02:28

draw a little sketch on the test to make it

02:30

clear There's No reason to struggle harder than you need

02:32

that's True in physics or in tug of war sometimes

02:35

the best way to win Yeah just let go No