I totally forgot that I am having meeting at my work place. All of sudden, I remembered that meeting through a hint given by my colleague while having discussion about our project work. I have to present a topic which I didn't prepare yet. Meeting is at 1.15pm. OMG! It's already 12.30 pm. Within few minutes I went to the meeting place with my topic. When I entered the meeting hall, the time was 12.53pm. I was happy to know that I arrived 22 minutes earlier.
You didnt list any graph?? Can you add it please :)
What you must do in this case is to find the roots of the polynomial.
We have then:
x ^ 2 + 20x + 100 = 36
Rewriting:
x ^ 2 + 20x + 64 = 0
The values of the roots are:
x1 = -4
x2 = -16
Remember that the values of the roots are what make the polinome zero
Answer:
x1 = -4
x2 = -16
It's difficult to make out what the force and displacement vectors are supposed to be, so I'll generalize.
Let <em>θ</em> be the angle between the force vector <em>F</em> and the displacement vector <em>r</em>. The work <em>W</em> done by <em>F</em> in the direction of <em>r</em> is
<em>W</em> = <em>F</em> • <em>r</em> cos(<em>θ</em>)
The cosine of the angle between the vectors can be obtained from the dot product identity,
<em>a</em> • <em>b</em> = ||<em>a</em>|| ||<em>b</em>|| cos(<em>θ</em>) ==> cos(<em>θ</em>) = (<em>a</em> • <em>b</em>) / (||<em>a</em>|| ||<em>b</em>||)
so that
<em>W</em> = (<em>F</em> • <em>r</em>)² / (||<em>F</em>|| ||<em>r</em>||)
For instance, if <em>F</em> = 3<em>i</em> + <em>j</em> + <em>k</em> and <em>r</em> = 7<em>i</em> - 7<em>j</em> - <em>k</em> (which is my closest guess to the given vectors' components), then the work done by <em>F</em> along <em>r</em> is
<em>W</em> = ((3<em>i</em> + <em>j</em> + <em>k</em>) • (7<em>i</em> - 7<em>j</em> - <em>k</em>))² / (√(3² + 1² + 1²) √(7² + (-7)² + (-1)²))
==> <em>W</em> ≈ 5.12 J
(assuming <em>F</em> and <em>r</em> are measured in Newtons (N) and meters (m), respectively).
Do the brackets first as it says in BIDMAS
