Answer:
sin  2θ = 1    θ=45
Explanation:
They ask us to prove that the optimal launch angle is 45º, for this by reviewing the parabolic launch equations we have the scope equation
             R = Vo² sin 2θ / g
Where R is the horizontal range, Vo is the initial velocity, g the acceleration of gravity and θ the launch angle. From this equation we see that the sine function is maximum 2θ = 90 since sin 90 = 1 which implies that θ = 45º; This proves that this is the optimum angle to have the maximum range.
We calculate the distance traveled for different angle
           R = vo² Sin (2 15) /9.8
           R = Vo² 0.051 m
In the table are all values in two ways
Angle (θ)                  distance R (x)
  0                 0                     0
15                 0.051 Vo²        0.5 Vo²/g
30                0.088 vo²        0.866   Vo²/g
45                0.102 Vo²        1   Vo²/g
60                0.088 Vo²      0.866   Vo²/g
75                0.051 vo²        0.5   Vo²/g
90                0                     0
See graphic ( R Vs θ)  in the attached ¡, it can be done with any program, for example EXCEL
 
        
             
        
        
        
The one that will change the velocity of a periodic wave is : 
B. Changing the medium of the wave
Waves is always determined by the properties of the medium, which means that changing the medium will change the velocity of the wave
hope this helps
        
                    
             
        
        
        
Thank you for posting
your question here at brainly. Feel free to ask more questions.
 
<span><span>The
best and most correct answer among the choices provided by the question is  </span>B.-2.71 V.</span>
 
Mg2+(aq) + 2e- -> Mg(s) E=-2.37 V
 
Cu2+(aq) + 2e- -> Cu(s) E =+ 0.34 V
 
Since Cu is acting as the anode, the equation needs to be
reversed.
 
Cu(s) -> Cu2+(aq) + 2e- E =- 0.34 V
 
Ecell= -2.37 V+ (- 0.34 V) = -2.71 V
 
<span><span>
</span><span>Hope my answer would be a great help for you. </span> </span>
<span> </span>
        
             
        
        
        
<span>Jun 16, 2012 - Given a temperature of 300 Kelvin, what is the approximate temperature in degrees Celsius? –73°C 27°C 327°C 673°C.</span><span>
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私は英語がわかりません sorry pls translate