Answer:
Efficent at low speeds.
Explanation:
Since water is 1,000 times more dense than air, electricity can generated from tides much more efficiently at slower speeds than wind turbines can.
 
        
             
        
        
        
Answer:
small guitar with no strings?
Explanation:
it would be fun to make i think
 
        
             
        
        
        
Answer:
use the dimensions shown in the figure
 
        
             
        
        
        
Answer:
(a) Flow rate of vehicles = No of vehicles per mile * Speed
=No of cars per mile * Speed +No of trucks per mile * Speed
= 0.75*50*60 + 0.25*50*40
=2750 vehicles / hour
(b) Let Density of vehicles on grade = x
Density on flat * Speed =Density on grade * Speed
So,( 0.75*50) * 60 + (0.25*50) * 40 = (0.75* x) * 55 + (0.25* x) * 25
So, x= 57.89
So, Density is around 58 Vehicles per Mile.
(c) Percentage of truck by aerial photo = 25%
(d)Percentage of truck bystationary observer on the grade= 25*30/60 * 25/55 =22.73 %