(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 13 N force with a fixed orientation does work on a particle as the particle moves through displacement = (3i - 5j + 3k) m. What is the angle between the force and the displacement if the change in the particle's kinetic energy is (a) +25.6 J and (b) -25.6 J?

2. Relevant equations

Angle = √(x^2 + y^2 + z^2)

Work = mad or F (dot) d

3. The attempt at a solution

I'm not sure how to approach this. I know that the dot product really just means to multiply the x parts by x parts, y parts by y parts, and z parts by z parts (or [itex]\hat{i}[/itex], [itex]\hat{j}[/itex], and [itex]\hat{k}[/itex] parts, if you prefer).

If the particle starts at (0, 0, 0), then the force would have caused it to go to its current position (3, -5, 3). I'm still not sure that is what is being said though.

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# Homework Help: Work in 3D

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