Answer:
The Earth's orbit makes a circle around the sun. At the same time the earth orbits around the sun, it also spins. In science, we cal that rotating on its axis. Since the earth orbits the sun AND rotates on its axis at the same time we experience seasons, day and night, and changing shadows throughout the day.
Answer:
maybe 14 or 15 im not good with this stuff im in 8th grade and im very very behind a lot im prob gonna delete this app cuz I dont understand anything
Answer:
x=25
Step-by-step explanation:
x+5+6x=180
7x+5=180
7x=175
x=25
Answer:
x = 0.954
Step-by-step explanation:
We apply pythagorean to find x
(4-x)² = 1.2² + 2.8²
(4-x)² = 9.28
✓(4-x)² = ✓(9.28)²
4 - x = 3.046
- x = 3.046 - 4
- x = -0.954
x = 0.954
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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).
