Velocity =displacement
Change in time
D=72km/hr
Time=20s
But the S.I unit of velocity is m/s so you woul have to change 72km/hr to m/s
Changing 72km to m
1 kilometer=1000meters
Then, 72 kilometers =?
72•1000/1
=72000m
Changing 72hours to seconds
If 1 hour = 3600 seconds
Then 72 hours=?
72•3600/1
=259200 seconds
Velocity =displacement
Change in time
V= 72,000
259,2005
=0.028m/s
Density depends on mass and volume so option D is correct answer. Hope this helps!
Answer:
it can cause huricans and flooding
Explanation:
Storm surge is the rising of the sea level due to the low pressure, high winds, and high waves associated with a hurricane as it makes landfall. The storm surge can cause significant flooding and cost people their lives if they're caught unexpected
To solve this problem it is necessary to apply the concepts related to the Centrifugal Force and the Gravitational Force. Since there is balance on the body these two Forces will be equal, mathematically they can be expressed as
![F_c = F_g](https://tex.z-dn.net/?f=F_c%20%3D%20F_g)
![\frac{mv^2}{r} = \frac{GmM}{r^2}](https://tex.z-dn.net/?f=%5Cfrac%7Bmv%5E2%7D%7Br%7D%20%3D%20%5Cfrac%7BGmM%7D%7Br%5E2%7D)
Where,
m = Mass
G =Gravitational Universal Constant
M = Mass of the Planet
r = Distance/Radius
Re-arrange to find the velocity we have,
![v^2 = \frac{GM}{r}](https://tex.z-dn.net/?f=v%5E2%20%3D%20%5Cfrac%7BGM%7D%7Br%7D)
At the same time we know that the period is equivalent in terms of the linear velocity to,
![T = \frac{2\pi}{\frac{v}{r}}](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7B2%5Cpi%7D%7B%5Cfrac%7Bv%7D%7Br%7D%7D)
![v = \frac{2\pi r}{T}](https://tex.z-dn.net/?f=v%20%3D%20%5Cfrac%7B2%5Cpi%20r%7D%7BT%7D)
If our values are that the radius of mars is 3400 km and the distance above the planet is 100km more, i.e, 3500km we have,
![v^2 = \frac{GM}{r}](https://tex.z-dn.net/?f=v%5E2%20%3D%20%5Cfrac%7BGM%7D%7Br%7D)
![( \frac{2\pi r}{T})^2 = \frac{GM}{r}](https://tex.z-dn.net/?f=%28%20%5Cfrac%7B2%5Cpi%20r%7D%7BT%7D%29%5E2%20%3D%20%20%5Cfrac%7BGM%7D%7Br%7D)
![T = \sqrt{\frac{4\pi^2 r^3}{GM}}](https://tex.z-dn.net/?f=T%20%3D%20%5Csqrt%7B%5Cfrac%7B4%5Cpi%5E2%20r%5E3%7D%7BGM%7D%7D)
Replacing we have,
![T = \sqrt{\frac{4\pi^2 (3500*10^3)^3}{(6.67430*10^{-11})(6.42*10^23)}}](https://tex.z-dn.net/?f=T%20%3D%20%5Csqrt%7B%5Cfrac%7B4%5Cpi%5E2%20%283500%2A10%5E3%29%5E3%7D%7B%286.67430%2A10%5E%7B-11%7D%29%286.42%2A10%5E23%29%7D%7D)
![T = 6285.09s (\frac{1min}{60s})(\frac{1hour}{60min})](https://tex.z-dn.net/?f=T%20%3D%206285.09s%20%28%5Cfrac%7B1min%7D%7B60s%7D%29%28%5Cfrac%7B1hour%7D%7B60min%7D%29)
![T= 1.74hour](https://tex.z-dn.net/?f=T%3D%201.74hour)
Therefore the correct answer is C.
11.86 years. Usually memorized as "12 years".