Physics Question Help Please! - First year physics/bridging course (1 Viewer)

[amour]

Hi BOS,
Sorry Mods- not sure where to put this thread.

Please help me work out how to do this.
Torque= force x radius

If force = 5i + 7j
and radius = 3i -2j

find torque.
Is this dot product where I go.. 5x3 + 7x-2
so torque = 1??

 

[soloooooo]

I would think it would equal 15i -14j. A weird question though.

 

[Dylanamali]

Hi BOS,
Sorry Mods- not sure where to put this thread.

Please help me work out how to do this.
Torque= force x radius

If force = 5i + 7j
and radius = 3i -2j

find torque.
Is this dot product where I go.. 5x3 + 7x-2
so torque = 1??

hey amour,
how come your asking a phys question?
do you need it for optom =/ ?

 

[amour]

I would think it would equal 15i -14j. A weird question though.

Oh thanks for your response. Can you confirm if I use dot product?

hey amour,
how come your asking a phys question?
do you need it for optom =/ ?

Hey Yes physics is compulsory for optom for first year. not too fond of physics atm

 

[Dylanamali]

oh okay, so are you just self-learning the whole HSC course?
or prelim and HSC??

 

[M99952011]

Is this HSC Physics? :O Everything has flown out of my head since HSC finished, I don't remember doing any of this. @_@

 

[amour]

oh okay, so are you just self-learning the whole HSC course?
or prelim and HSC??

No, this is introduction to First year physics- through the UNSW Physics bridging course.

 

[Ferox]

Torque= radius x force
=(3i -2j) x (5i + 7j)
=21k - (-10)k
=31k

 

[soloooooo]

Torque= radius x force
=(3i -2j) x (5i + 7j)
=21k - (-10)k
=31k

How did you do that?

 

[Drongoski]

I think he used the cross product

yep.



Of course you'd not have done this in your HSC.

 

[soloooooo]

Thanks, I had forgotten you had to use the cross product.