WORK DONE ENERGY QUESTION

[sage mirage]

can aynone help?

with mechanic

furhter math

<@&791435371564892232>

[gusty elk]

Show me what you’ve done so far

I got 7.78

Can u check if that’s right @sage mirage

[sage mirage]

oh mb

i did a

how to do B?

EK=GPE+EK i think or

im not sure whats happening

i see EK

[gusty elk]

EK?

Or u mean kinetic energy

[sage mirage]

kinetic energy

same

E lower case K

[gusty elk]

Hold up

BRUH

I wrote tan = 3/7 😭

I legit can’t read

2/7*

• was reading the wrong thing

Wait I’ll show u in a second I’m just redoing it

I’m sending it now

@sage mirage

[sage mirage]

oh my bad

16G

where did 16g come from

why is the reaction force 16g

i found what alpha was

26.8

36.8

[gusty elk]

Resolve vertically

No u don’t find alpha

U never find alpha in questions like this

[sage mirage]

wdym

you can find alpha

[gusty elk]

Using the triangle

3 4 5 triangle

U don’t need it

[sage mirage]

i used it to find the reaction force

[gusty elk]

Ure not meant to do it like that

[sage mirage]

lol maths be like

jkjkjk

ok whats the way to do it

without the alpha

[gusty elk]

So u can substitute exact values in to make like 100x easier

Use this method

[sage mirage]

hmm

how do you know what alpha is tho

why is alpha 4/5

[gusty elk]

Wdym

[sage mirage]

ohh 4/3

why is it 4/3

[gusty elk]

Sorry 😭 my handwriting kinda bad

Because if u resolve vertically

[sage mirage]

wait is that 3 or 5

[gusty elk]

R=4gcosa

[sage mirage]

yep

[gusty elk]

5

[sage mirage]

whats a then?

[gusty elk]

Wdym a

[sage mirage]

in here

[gusty elk]

Ure substituting exact values for cos

[sage mirage]

the reaction force= 4g x cos(a)

why subsitute exact values

[gusty elk]

Cosa=4/5 from here

[sage mirage]

why tho

why not 5/6

or 5/7

or 8/9

[gusty elk]

Tan = O/A

Create a triangle

Label ure opposite 3 and adjacent 4

[gusty elk]

Find missing length using Pythagoras

[sage mirage]

345

5

if it as o/a woudlnt it be 3/4

why is it 4/5

[gusty elk]

Cosa=a/h

[gusty elk]

Yep

Use trig ratios

To find cosa and sina

[sage mirage]

why dont we just use sin a = 3/4

oh wait

i meant

[gusty elk]

Wdym

[sage mirage]

tan a = 3/4

ohhh wait

i see what you did

nvm

im used to find the angles way to much

nvm just substituet

[gusty elk]

Yh get used to this

It’s better

[sage mirage]

yeah agree

dd

wait

is it EK=WD+EP?

[gusty elk]

KE=GPE+WDF

[sage mirage]

kinetic energy = work done + gravitational potential energy

[sage mirage]

yea

[gusty elk]

Good

[sage mirage]

wait why is it WDF

[gusty elk]

It’s work done by friction tho remember tho

Because there’s a frictional force

[sage mirage]

work done = 22.6

so 22.6 + mgh right?

[gusty elk]

work done for the friction is 22.6

[sage mirage]

ye

[gusty elk]

Yh

[sage mirage]

ok i love the conservation of energy principle

lol

whats h tho

4?

[gusty elk]

No

work it out

Look what I did

[sage mirage]

ah 2.5(3/5)

h= 2.5(3/5)

where did these numbers come from

oh wait

what are the components

[gusty elk]

It’s the vertical component for the height

[sage mirage]

yeah

[gusty elk]

The angle is still alpha

Use trig ratio

To find the opposite

[sage mirage]

sin a = x/2.5

[gusty elk]

Go

So 2.5sina=x

[sage mirage]

yeah

[gusty elk]

Then put that in GPE

[sage mirage]

but then it would be 2.5sina x 4g +22.4

[gusty elk]

Yh

=KE

[sage mirage]

ohhh right

we know a

wait

3/5 = sin a ?

[gusty elk]

YH

[sage mirage]

where is 3 and 5 in this

[gusty elk]

Wdym 😭

There’s not meant to be 3 and 5

You should watch this video

[sage mirage]

h = 2.5(3/5)

[gusty elk]

https://youtu.be/VJzsSqDe90E

[sage mirage]

WE said that h = 2.5sina

[gusty elk]

You’ll understand it after u watch this

[sage mirage]

h = 2.5sina , h = 2.5(3/5), how is sin a = (3/5)

h=

is this like a 4markker

question

[gusty elk]

Yh

I’ll explain later I gtg

[sage mirage]

alrighty

thanks

for helpinmg