Resolving Forces (1 Viewer)

[Smithereens]

How the heck do you resolve forces? Say we've got a vertical and horizontal component, and we had the forces T (thrust on a side bank going outwards), N and mg acting upon it. How would you know when to add or minus both forces when you're looking at each individual component? Do vectors come into play?

Thanks

 

[tacogym27101990]

How the heck do you resolve forces? Say we've got a vertical and horizontal component, and we had the forces T (thrust on a side bank going outwards), N and mg acting upon it. How would you know when to add or minus both forces when you're looking at each individual component? Do vectors come into play?

Thanks

yeah its all just vector addition

 

[Trebla]

How the heck do you resolve forces? Say we've got a vertical and horizontal component, and we had the forces T (thrust on a side bank going outwards), N and mg acting upon it. How would you know when to add or minus both forces when you're looking at each individual component? Do vectors come into play?

Thanks

Break up the vectors into their components by making the final vector the hypotenuse of a right-angled triangle.
You can only add vectors if they are in the same direction. So if you have two vectors pointing in the same direction, you can add them up.
The negative of a vector is the same vector except in the opposite direction.
So for example, if mg is downwards and the vertical component of N is upwards, then you can't directly add them because they're not in the same direction. However, if you take the negative of the vector mg, this flips the direction upwards giving - mg. So then, you can now add the two upwards vectors together (e.g. Ncos a - mg = 0, if there is no net vertical force).

 

[cccclaire]

Oh man, this is the only thing in 4u I'm good at. I so hope we get a big conical pendulum question, or motion on a banked track. That would be so sweet.

But basically what the person above me said is right.

Draw in a right angled triangle for each force, and then figure out both the horizontal and vertical forces using simple triganometry (SOH CAH TOA). Then you can add all your horizontal forces and vertical forces.

 

[tacogym27101990]

oi in that jeff geha 50 tips thingy
he says the conical pendulum which revolves on a cone or parabaloid is the hardest thing in 4 unit maths
does anyone else think that it actually not that hard??

 

[midifile]

oi in that jeff geha 50 tips thingy
he says the conical pendulum which revolves on a cone or parabaloid is the hardest thing in 4 unit maths
does anyone else think that it actually not that hard??

when i first did mechanics I was like 'kill me now', but once I got my head around all the concepts, its actually pretty easy

especially because a lot of questions are 'prove ...' or kinda tell you how to do the question

 

[cccclaire]

oi in that jeff geha 50 tips thingy
he says the conical pendulum which revolves on a cone or parabaloid is the hardest thing in 4 unit maths
does anyone else think that it actually not that hard??

they're difficult to understand at first.

Once you understand them, they're piss easy.

 

[tommykins]

回复: Re: Resolving Forces

yeah mechanics wasn't as hard as i thought it'd be?

it'd be up there with conics in terms fo just tedious algebra bashing.

maybe physics is helping me here

 

[vds700]

oi in that jeff geha 50 tips thingy
he says the conical pendulum which revolves on a cone or parabaloid is the hardest thing in 4 unit maths
does anyone else think that it actually not that hard??

Yeah i reckon its not that bad, all you really need to do is break up the tension and normal reaction forces into horizontaal and vertical components and form equations. Once you've got the equations, its pretty easy.

My teacher set a bitch of a Q in an assessment a while ago, it had a particle spinning in a conical pendulum, but another particle connected to it spinning as well, but making a greater angle with the vertical, and we had to prove some stuff. I was lie wtf??

 

[jkwii]

trig... trig... its all trig and algebra in mechanics. most of the time you will only get 2-3 forces to resolve - tension/normal, reaction, gravity