Answer: Brownion motion is the erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium.
Explanation:
Brownian motion is the random movement of particles in a fluid due to their collisions with other atoms or molecules. 
 
        
             
        
        
        
Answer:
v = 15.65 m/s
Explanation:
We use conservation of mechanical energy between initial (i) and final (f) states:
Pi + KEi = Pf + KEf
At the top of the cave at the instant the bat starts to fall, there is only potential energy since the bat's velocity is zero.
Pi = m g h = 600 J
and the KEi = 0 J (no velocity)
Knowing the height of the cave's roof (12.8 m) , we can find the mass of the bat:
m = 600 J / (g 12.5) = 4.9 kg
Using conservation of mechanical energy, the final state is:
Pf + KEf = 600 J 
with Pf = 0 (just touching the ground)
KEf= 1/2  4.9 (v^2)
and we solve for the velocity:
600 J = 0 + 1/2  4.9 (v^2)
v^2 = 600 * 2 / 4.9 = 244.9
v = 15.65 m/s
 
        
             
        
        
        
The earth is 4.54 billion years old.
        
                    
             
        
        
        
<span>The contact force that acts on objects in a liquid or gas and allows objects to float is called    </span>Buoyancy.