die riao :(

Y_Shun SG

i need help on physics on force. how to calculate the force etc..can anybody help me? Sad

i oso need help in chemistry...on how to calculate mole etc. (mole still ok, but some qtns on find how many blahblah when there 12g of xx) Sad

Unidentified SG

check your textbook , all fomula are written there !! Dun be lazy

Y_Shun SG

i know formula, but i dunno how to apply Embarassed

omgz! its all those diagonestic tests...=( i scare i cannot make it Crying or Very sad

Unidentified SG

Force = Mass x Accelaration

find the object mass(kg) then times the accelarion value (m/s)

what do you mean by dont know how to apply

hisoka SG

really don’t know want to help you lor not, these answers can be easily found from text and teachers

mir4cle SG

Chemistry:

No of moles = mass/Mr

No of moles = volume/24dm^3

No of moles = conc x volume

Physics:

F = ma
....
erm..yeah..

thoreldan SG

this is a mole

Hogzilla SG

May the force be with you.

aiglosicicle SG

go find your teacher for one-to-one consultation. no good teacher will reject a student in serious need of some help.

Y_Shun SG

k..i post 1 qtn here...
question copyright to my secondary sch.

a. Calculate the position of the centre of mass of the seat and plank. [3m]

b. If a victim of mass 75 kg is strapped onto the seat, calculate the additional force required to be applied on the counter-balance stone to balance the instrument. [2m]

pervertboi SG

Shocked Shocked Shocked
I was about to post that Question Exclamation

iLuVpOrKyPiG SG

engineering math?

knn, i hate such things.

Embarassed

Hogzilla SG

Congratulation!!

You earned a "Look down" from me.

Hogzilla SG

That's what my PC said to us (the whole company) when we first took IPPT as recruit.

hisoka SG

this one is use moments not force de. anywya in this case force = mg mass x gravitational accelerration.

just balance the moments and i think you will get the answer.

and hor its mols i think

Unidentified SG

how come moment question nowaday use example like torture tool ? Lowering the victim into cold water some more ,

Y_Shun SG

btw whats mols?

if moment, can exprain n work it out for me anot? thxzz!! rly appreciate ur help!!

hisoka SG

taking moments on the plank about the pivot.

1*2 = (4-x)*1.2 then solve

then get x lor then you know the position of the c.g. le.

1 is the relative weight of the stone and 1.2 is the relative weight of the plank + seat( which acts thru the c.g.

erm 1 mol = a certain number of molecules of the molecule. the numebr is the alvagadro number

hegu SG

a) clockwise moment = anticlockwise moment
1000(10) x 2.0 = (4.0 - x) x 1200(10)
x = 2.33 m

b) Let M be the mass to balance
M x 2.0 = 75 x 4.0 + 1200 x 1.667
M = 1150 kg

Additional mass = 1000-1150 = 150 kg = 1500N of additional force