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vectors

plz help me on this question,part b says to express in terms of dot and cross so is it two answers or can u express using one answer?
regards
(edited 9 years ago)
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Original post by lopper
plz help me on this question,part b says to express in terms of dot and cross so is it two answers or can u express using one answer?
regards


It is just one ansdwer that is required involving both dot and cross products.
Reply 2
Avatar for VannR
VannR
21
If you don't know how to answer this question, you need to revise the vectors in FP3 and make sure that you have a sound understanding of the geometrical interpretations of the scalar and vector products. This is what you need to know. Answer the question from first principles.

I would go into more detail, but its been a while since June and I only remember about 80% :P
(edited 9 years ago)
Nightmares...

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Reply 4
Avatar for lopper
lopper
OP
Original post by brianeverit
It is just one ansdwer that is required involving both dot and cross products.

ya could tell me the process to solve this
Reply 5
Avatar for lopper
lopper
OP
Original post by VannR
If you don't know how to answer this question, you need to revise the vectors in FP3 and make sure that you have a sound understanding of the geometrical interpretations of the scalar and vector products. This is what you need to know. Answer the question from first principles.

I would go into more detail, but its been a while since June and I only remember about 80% :P

thanks a lot :confused:,but no offense i dont need u to tell me that lol
Reply 6
Avatar for kara1
kara1
11
Original post by lopper
plz help me on this question,part b says to express in terms of dot and cross so is it two answers or can u express using one answer?
regards



Why don't you show us what you've done so far or tell us what you have tried to find yourself 'stuck'. We're not just going to give you the answer...
Reply 7
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VannR
21
Original post by lopper
thanks a lot :confused:,but no offense i dont need u to tell me that lol


From the fact that you don't know how to answer this question, yes, you do need someone to tell you this.

Create a diagram and define the different vectors using vector notation. The apply the geometrical interpretation of the scalar and vector products to the problem to find the answer.

A good explanation of this process for solving problems involving vectors is in Mathematical Methods for the Physical Sciences by Mary L. Boas. You can get this for free on the internet, but I will not link copyrighted material here.
Some things you can ponder about:

Area of a parallelogram can be interpreted as twice that of the area of one half of itself, ie a triangle.

Do you know how to discover the area of a triangle via vector cross product?

In the basic geometric formula for the area of a parallelogram where it is given as length of base multiplied by its perpendicular height, can you recognize that the length of its base is in fact equivalent to the distance between two parallel sides?

Can you reconcile both suggested ideas?

Hope the above helps. Peace.
Reply 9
Avatar for lopper
lopper
OP
Original post by WhiteGroupMaths
Some things you can ponder about:

Area of a parallelogram can be interpreted as twice that of the area of one half of itself, ie a triangle.

Do you know how to discover the area of a triangle via vector cross product?

In the basic geometric formula for the area of a parallelogram where it is given as length of base multiplied by its perpendicular height, can you recognize that the length of its base is in fact equivalent to the distance between two parallel sides?

Can you reconcile both suggested ideas?


Hope the above helps. Peace.

thanks i did the same i got the area of parrallelgrom=|vecpq*n| is that correct
thanks
Reply 10
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lopper
OP
Original post by kara1
Why don't you show us what you've done so far or tell us what you have tried to find yourself 'stuck'. We're not just going to give you the answer...

i got up until the area of parrallelogram i used |vecpq*n| is that correct
thanks

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