Answer:
A Chinese Geomancer
Explanation:
The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD where it was called the "south-governor" or "South Pointing Fish" (sīnán 司南). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese.
However, it is believed Flavio Gioia first invented the refined compass, and a monument has been erected in Almafi Italy to honor his invention. The magnetic compass was probably developed by combining the wind rose and the lodestone. From this device it is supposed the compass rose evolved.
Explanation:
Given that,
2 strings both vibrate at exactly 220 Hz. The frequency of sound wave depends on the tension in the strings.
The tension in one of them is then decreased sightly, then
will decrese.
Beat frequency, 

So, the new frequency of the string is 217 Hz. Hence, this is the required solution.
Answer:
10392.30N
Explanation:
We proceed by computing the individual force exerted by the boats
For the first boat
The angle is 30 degree to the vertical
Hence
Force = F cos θ
F=6000 cos 30
F=6000*0.866
F=5196.15 N
Since the boats are two and also at the same angle and also exerting the same force
The Net force = 2*5196.15
Net force=10392.30N
To develop this problem we will apply the concepts related to the kinematic equations of motion, specifically that of acceleration. Acceleration can be defined as the change of speed in an instant of time, mathematically this is

If a mobile is decreasing its speed (it is slowing down), then its acceleration is in the opposite direction to the movement. This would imply that the acceleration vector is opposite to the velocity vector.
Therefore the correct answer is B.
The prefix for oxygen in As2O5 is PENTA.
Penta is used to show that the number of oxygen atoms present in the compound is five. Penta means five, while mono mean one, di means two, tri means three and tetra mans four and so on. The chemical name for the given compound is Arsenic pentoxide.