Answer:
<em>Magnetic</em><em> </em><em>compass</em><em> </em><em>helps</em><em> </em><em>to </em><em>identify</em><em> </em><em>direction</em><em> </em><em>in </em><em>this </em><em>way </em><em>,</em><em> </em><em>this </em><em>compass</em><em> </em><em>work </em><em>because</em><em> </em><em>of </em><em>earth</em><em> </em><em>magnetic</em><em> field</em><em> </em><em>and </em><em>show</em><em> </em><em>us </em><em>direction</em><em> </em>
<em> </em><em> </em><em>hope</em><em> it</em><em> helps</em><em> and</em><em> your</em><em> day</em><em> will</em><em> be</em><em> full</em><em> of</em><em> happiness</em><em>. </em>^_^
You can try to explain it by using a parallel between their and your societies .
Answer: 49.5 m
Explanation:
The speed of sound 
is given by a relation between the distance 
and the time 
:
(1)
Where:
is the speed of sound in air (taking into account this value may vary according to the medium the sound wave travels)
since we are told th hunter was initially 412.5 meters from the cliff and then moves a distance 
towards the cliff
Since the time given as data (2.2 s) is the time it takes to the sound wave to travel from the hunter's gun and then go back to the position where the hunter is after being reflected by the cliff
Having this information clarified, let's isolate and then find :
(2)
(3)
Finding :
This is the distance at which the hunter is from the cliff.
Image from a far away object formed by a concave mirror
I have no idea but this is my best guess as a sophomore in college
Answer:
2.23 × 10^6 g of F- must be added to the cylindrical reservoir in order to obtain a drinking water with a concentration of 0.8ppm of F-
Explanation:
Here are the steps of how to arrive at the answer:
The volume of a cylinder = ((pi)D²/4) × H
Where D = diameter of the cylindrical reservoir = 2.02 × 10^2m
H = Height of the reservoir = 87.32m
Therefore volume of cylindrical reservoir = (3.142×202²/4)m² × 87.32m = 2798740.647m³
1ppm = 1g/m³
0.8ppm = 0.8 × 1g/m³
= 0.8g/m³
Therefore to obtain drinking water of concentration 0.8g/m³ in a reservoir of volume 2798740.647m³, F- of mass = 0.8g/m³ × 2798740.647m³ = 2.23 × 10^6 g must be added to the tank.
Thank you for reading.
