How Do You Calculate Force in Vector Form?

[williamwong0402]

Hi everyone

please help
how can i find the force in Q(a)(ii)?

 

[Andrew Mason]

Welcome to PF William!

A unit vector is just the vector ie. (x, y z) divided by its length. What is the length of this vector (1,1,1)?

You must then express the force as a vector by multiplying the magnitude of tbe force (14 N) by the unjt vector in the direction of that force.

Can you provide us with the expression for Work in terms of the information provided?

AM

 

[williamwong0402]

like this?
but how can get force of vector by multiplying

 

[Buffu]

but how can get force of vector by multiplying

I did not get it. Can you please state it clearly.
But I guess you mean how to express Force in vector form. That is simply ##{14\over\sqrt{3}}\hat{i} + {14\over\sqrt{3}}\hat{j} +{14\over\sqrt{3}}\hat{k}##.

For (iv) you need to take dot product of (ii) and (iii). ##(\vec{A}\cdot\vec{B} = A_xB_x + A_yB_y + A_zB_z)##

 

[williamwong0402]

I did not get it. Can you please state it clearly.
But I guess you mean how to express Force in vector form. That is simply ##{14\over\sqrt{3}}\hat{i} + {14\over\sqrt{3}}\hat{j} +{14\over\sqrt{3}}\hat{k}##.

For (iv) you need to take dot product of (ii) and (iii). ##(\vec{A}\cdot\vec{B} = A_xB_x + A_yB_y + A_zB_z)##

Thank you ~i got it
i just thought the other way more complex