Answer:
a) 
b) 
c) 
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height

To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height



So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point



Solving the quadratic equation



So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:


Since the projectile is going down the velocity at the instant it reaches the ground is:

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.
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Answer:
Explanation:
The amplitude of resultant wave as the result of overlap of two waves depends upon the phase difference between the two. If the waves meet crest to trough , the phase difference is 180 degree or they are in opposite phase . Hence they will destroy each other . The amplitude of resultant wave can be obtained by subtracting the amplitudes of two waves. They will interfere destructively.
Amplitude of resultant gives waves = 4.6 - 2 = 2.6 cm.
Plants,such as trees poduce oxygen to help animals like insects or humans can bresth snd surviave.
Answer:

Explanation:
A polarizer changes the orientation of the oscillations of a light wave.
I₀ = Intensity of unpolarized light = 10
θ = Angle given to the polarizer = 60°
Intensity of light
I = I₀cos²θ
⇒I = 10cos²60

So, the after passing through the second polarizer is 