Physics Pro?

[Beehive3783]

Your avatar is ethylene but you cant do physics

Ethylene and molecules should be chemistry right?

[Cerano]

FYI this is sec 3 final year exam qns !

 

find it quite believable remember my son mugging this away in sec 3 too

[Josho]

im totally @.@

[Altivo]

not difficult mah. Downward moment must equal to upward moment

 

Downward moment = centre of gravity x distance from pivot = 0.4m x 800N = 320NM

 

Upward moment = 0.9m x Y = 0.9Y

 

Now since both moments are equal to each other ---> 0.9Y = 320, so Y = 320/0.9 = 356N

[Zyrofillica]

Eh no la. He still needs some "N". Cannot be 0N confirm guarantee + chop. Maybe his effort threshold is 1 billion N and so his percentage of effort - 0.00000000000000000000000000000000000000000000000001% ~ 0%

 

no la he can affect gravitational field, else how can he actually fly? so he affects the field around the wheelbarrow makeing it a negative field, hence the wheelbarrow floats on its own when he touches it, he is actually applying downward force to keep it from flying into space!

[Porker]

all of u are wrong. superman carries the wheelbarrow. he does not follow the laws of physics so it takes 0N of effort for him to lift the wheel barrow!!!

 

I also say

 

Simple moments question must spread to so many pages

[Ethene]

Your avatar is ethylene but you cant do physics

 

and you don't know the difference between physics and chemistry

[Mivec9]

and you don't know the difference between physics and chemistry

 

aiyoh cant blame him. that's last or last few chapters of chemistry for sec 4

 

[PointyEwe]

Technically due to the 'Slope' of the wheel barrow, the answer will have to be higher than 356N.

 

The calculated force F should be 90degree with regards to the slope of the wheel barrow and not 90degree with the horizontal floor.

 

Apply the answer F in the vertically 90degree(wrt floor) will create a small horizontal force component, which will drag the wheel barrow backwards instead.

 

The backward vector force sharing will 'reduce' the 356N 90deg vertical force that is required to lift the wheel barrow.

 

So F=356N vertically will NOT be sufficient to lift the wheel barrow!

 

One should calculate the F as turning moment, aka 90deg wrt to the slope of the wheel barrow handle bar!!!

 

Now we need to know the degree of the wheel barrow slope to determine the answer.

 

Surely 356N is not accurate.....so the next highest 444N could be the answer!!~!

 

 

Erm.....

 

It is better to remain silent and be thought a fool than to open one's mouth and remove all doubt

[Headshok]

wah u all explain until dam cheem.

 

tot this one is simple moments

 

clock wise = anti clock wise?

 

so taking moments about the wheel ,

 

clock wise moments = anti clock wise moments

0.4x 800 = (0.4+ 0.5)x F

320 = (0.9) x F

 

thus F = 320 / (0.9)

= 355.5555

 

This would be the easiest way to explain to whoever you are teaching :)

 

hope this helps mate

 

cheers

 

 

[Xers007]

hmmm... think its not easy to be a dad eh.... all these subjects all these qns....

[Little_prince]

knn...

 

my msc can throw away liaoz

 

i totally catch no ball...