Because one pole of the Earth's axis of rotation (the North one) points
almost exactly toward Polaris.
If Polaris had a pimple or a bump somewhere on its edge, you'd see
the bump rotate around the whole edge, like a clock, once a day. But
the whole star appears to stay in one place, because our axis points to it.
Answer:
2940.1 joules would you burn in climbing stairs all day.
Explanation:
Work = W = F
d
going up stairs would be against force of gravity
W = mgh
where h is the height
the question is not complete because we need speed or distance
h = v
t
so assuming 1 step per second
h = 86,400 steps
7inchs/step
0.0254 m/inch
h = 15362 m
so from this
W = 800 N
15362
= 12289600 J
that means YOU need 12289600 J to walk 1 step per second all day
divide that by 4180 J /Kcal
Kcal = 
= 
= 2940.1 Kcal
if you ran faster you would use more energy 2 steps per second would mean 5880 Kcal.
A object that has been reinvented so it is more energy efficient
We assign the variables: T as tension and x the angle of the string
The <span>centripetal acceleration is expressed as v²/r=4.87²/0.9 and (0.163x4.87²)/0.9 = </span><span>T+0.163gcosx, giving T=(0.163x4.87²)/0.9 – 0.163x9.8cosx.
</span>
<span>(1)At the bottom of the circle x=π and T=(0.163x4.87²)/0.9 – .163*9.8cosπ=5.893N. </span>
<span>(2)Here x=π/2 and T=(0.163x4.87²)/0.9 – 0.163x9.8cosπ/2=4.295N. </span>
<span>(3)Here x=0 and T=(0.163x4.87²)/0.9 – 0.163x9.8cos0=2.698N. </span>
<span>(4)We have T=(0.163v²)/0.9 – 0.163x9.8cosx.
</span><span>This minimum v is obtained when T=0 </span><span>and v verifies (0.163xv²)/0.9 – 0.163x9.8=0, resulting to v=2.970 m/s.</span>
Im not exactly sure but I think the answer is techtonic plates collide