Answer:about 200,000 years ago that humans existed on earth.
Explanation:Geologic time refers to the planet's changing geology. The earliest fossils of modern humans are from the middle Paleolithic about 200,000 years ago such as the omo remains from Ethiopia and the fossil of herto classified equally as homosapiens equally from Ethiopia.
Distance of lake a is 200 km at 20 degree north of east
distance between lake a and b is 230 km at 30 degree west of north
now the distance between base and lake b is given as

given that




now the total distance is


now the magnitude of the distance is given as


also the direction is given as


<em>so it is 277.4 km at 74.7 degree North of East</em>
in china, there is a family limit for only having 1 child
at 10 billion people on earth, we will most likely run out of food supply
Answer:

Explanation:
The rotation rate of the man is:



The resultant rotation rate of the system is computed from the Principle of Angular Momentum Conservation:
![(90\,kg)\cdot (5\,m)^{2}\cdot (0.16\,\frac{rad}{s} ) = [(90\,kg)\cdot (5\,m)^{2}+20000\,kg\cdot m^{2}]\cdot \omega](https://tex.z-dn.net/?f=%2890%5C%2Ckg%29%5Ccdot%20%285%5C%2Cm%29%5E%7B2%7D%5Ccdot%20%280.16%5C%2C%5Cfrac%7Brad%7D%7Bs%7D%20%29%20%3D%20%5B%2890%5C%2Ckg%29%5Ccdot%20%285%5C%2Cm%29%5E%7B2%7D%2B20000%5C%2Ckg%5Ccdot%20m%5E%7B2%7D%5D%5Ccdot%20%5Comega)
The final angular speed is:
