Fe + 3NaBr → FeBr3 + 3Na
The Na is replaced by the Fe atom.
 
        
                    
             
        
        
        
The answer is : C. reduce their input force
they put wax on their kayak to make their boat cut smoothly through the water, which make it able to obtain further distance with less input force, which will increase it's overall speed 
        
                    
             
        
        
        
117 333.333 m-1 your welco
        
                    
             
        
        
        
Answer:
m = 50.74 kg
Explanation:
We have,
Initial temperature of water is 20 degrees Celsius
Final temperature of water is 46.6 degrees Celsius
Heat absorbed is 5650 J
It is required to find the mass of the sample. The heat absorbed is given by the formula ad follows :

c is specific heat of water, c = 4.186 J/g°C
So,

So, the mass of the sample is 50.74 kg.