All Questions
4
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Why is time taken to go around the Sun to cover a small fixed angle proportional to the square of the distance?
I am reading Feynman's lost lecture. At this point, he asks us to consider points J, K, L and M which subtend equal angles at the sun S. And then he claims that triangles JKS and KLS are similar ...
- 430
0
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1
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949
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Proving the centre of mass formula with integral [closed]
I came across a question:
Find $f(r)$ and prove the centre of mass formula:
$$\vec{r_{cm}} = \frac{1}{V} \int f(r) \vec{dS} $$
Where $V$ is the total volume and our surface integral is ...
- 113
2
votes
1
answer
81
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Satellite and gravitational acceleration
According to $0.5gt^2$ object will fall 5m in first second.
Earth curve is 5m for 8km
So if we can project object at 8000 m/s speed object will never fall into ground.
Above scenario is correct for ...
- 29
3
votes
2
answers
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Falling rain drop problem [closed]
EDIT: I've read that a ball moving in a rectilinear motion with a non-constant radio, $r$ satisfies that
$$\frac{dV_c}{dy} = \pi r^2,$$
where $V_c$ is the volume swept by the ball and $y$ is the ...
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