Answer:

Explanation:
= Permittivity of free space = 
A = Area
h = Altitude = 600 m
Electric flux through the top would be
(negative as the electric field is going into the volume)
At the bottom

Total flux through the volume

Electric flux is given by

Charge per volume is given by

The volume charge density is 
Answer:
0.872<em>m/s</em>
Explanation:
Tangential velocity is given by the formula,

In the question given,
radius= 25meters
time= 180secs
pie= 3.14
number of laps= 1
The magnitude of tangential velocity equals;

<em>v </em>= 157<em>m</em>/180<em>secs</em>
Therefore, the magnitude of the tangential velocity
=0.872<em>m/secs</em>
False. it's depend on g -constant.
"Changing water salinity" is the most significant challenge for organisms that live in estuaries.
<u>Answer:</u> Option D
<u>Explanation:</u>
For estuaries, alkalinity levels are usually the maximum at a river's mouth where the ocean water falls for, and the minimum upstream where freshwater falls in. Although salinity vary throughout the tidal cycle. In estuaries, salinity rates usually decrease in spring as snow melt and rain raises the freshwater flow from streams and groundwater.
It influences the chemical environments within the estuary, especially the dissolved oxygen (DO) levels in the water. The level of oxygen that would get dissolved in water or its solubility get declined when the alkalinity rises.
Direction. Velocity is a vector that describes both speed and direction, while speed is a scalar that describes only speed regardless of direction.