Answer:
<em>UP</em>
Explanation:
heat flows from higher level to lower level
( higher concentration to lower concentration )
and since temperature in above block is less than the lower block, the heat will flow from lower block to higher block .
( Up )
 
        
             
        
        
        
Answer:
The angular velocity of the propeller is 2.22 rad/s.
Explanation:
The angular velocity (ω) of the propeller is:  
 
                              
Where:
θ: is the angular displacement = 10.6 revolutions 
t: is the time = 30 s 

Therefore, the angular velocity of the propeller is 2.22 rad/s.
I hope it helps you!
 
        
             
        
        
        
Answer: to avoid problems with water supply 
Explanation: power plant needs water to run
 
        
                    
             
        
        
        
Here the block has two work done on it
1. Work done by gravity
2. Work done by friction force
So here it start from height "h" and then again raise to height hA after compressing the spring
So work done by the gravity is given as

Now work done by the friction force is to be calculated by finding total path length because friction force is a non conservative force and its work depends on total path


Total work done on it

So answer will be 
None of these