Answer:
The moment of inertia decreased by a factor of 4
Explanation:
Given;
initial angular velocity of the ice skater, ω₁ = 2.5 rev/s
final angular velocity of the  ice skater, ω₂ = 10.0 rev/s
During this process we assume that angular momentum is conserved;
I₁ω₁ = I₂ω₂
Where;
I₁ is the initial moment of inertia
I₂ is the final moment of inertia

Therefore, the moment of inertia decreased by a factor of 4
 
        
             
        
        
        
Answer:
They weight the same, they're both 1 kilogram
 
        
                    
             
        
        
        
Countries longer day for example in the Middle East could benefit more but Alaska has more night like longer night which is why it would hard to benefit from the solar panels there.
Hoped this helped
        
             
        
        
        
Answer:
They can do this with the help of mechanical power generated from the human muscle.
Explanation:
Since rescue workers engage in missions where it is usually difficult for them to get electrical energy to their devices and working tools, they could employ various materials that can be sourced around them to get energy to their tools. One of such is the mechanical power generated from the human body through squeezing and compressing. 
Some green devices such as the dyno torch have been designed to be powered through this method. Repeated squeezing of its flywheel allows light to be generated.
 
        
             
        
        
        
The 2 spots after the decimal still counts toward the total  the figures