Did you try looking it up ?
        
             
        
        
        
Answer:
1. 0.574 kJ/kg
2. 315.7 MW 
Explanation:
1. The mechanical energy per unit mass of the river is given by:


Where:
Ek is the kinetic energy
Ep is the potential energy
v is the speed of the river = 3 m/s
g is the gravity = 9.81 m/s²
h is the height = 58 m 

Hence, the total mechanical energy of the river is 0.574 kJ/kg.
2. The power generation potential on the river is:

Therefore, the power generation potential of the entire river is 315.7 MW.
 
I hope it helps you!
 
        
             
        
        
        
55 Kg has a weight of 55x9.8= 539 N
That is equal to the Normal force.
The static friction = 0.19 x 539 = 102.4 N
        
             
        
        
        
Explanation:
The water cycle basically involves five steps:
- evaporation and transpiration ⇄
- condensation, ⇄
- precipitation, ⇄
- runoff, ⇄
- infiltration ⇄
So when a <u>thunderstorm </u>occurs it <em>helps in completing the precipitation process </em>by enabling the release of water vapor stored up in the atmosphere to fall on the ground as rain.
After this, the water <em>runoffs </em><em>to the surface of the ground, on plants, into rocks, rivers, and lakes.</em>
Next, the <em>Infiltration process</em> enables the water on the ground surface to enter the soil some of which becomes groundwater.
The cycle begins again as the<em> </em><em>evaporation and transpiration</em> <em>process </em>begins, where the groundwater as a result of heat from the sun is taken back into the atmosphere, while water in plants by means of transpiration goes back <em>into the atmosphere</em>.
It then <em>condenses </em>and falls back as precipitation again.
 
        
             
        
        
        
Mass of the bird(m) = 150 g = 0.15 kg
Speed (v) = 10 m/s
Kinetic Energy =  = 7.5 J
 = 7.5 J
Altitude (h) = 15 m
Gravitational Potential Energy = (0.15)(9.81)(15) = 22.0725 J
Mechanical Energy = Kinetic Energy + Potential Energy = 7.5 + 22.0725
= 29.5725 J