20600Cal               
Explanation:
Given parameters: 
Mass of water = 319.5g
Initial temperature = 35.7°C
Final temperature = 100°C
Unknown: 
Calories needed to heat the water = ? 
Solution: 
The calories is the amount of heat added to the water. This can be determined using;
      H  =   m  c Ф
 c  = specific heat capacity of water = 4.186J/g°C 
    H is the amount of heat 
     Ф is the change in temperature
     H = m c (Ф₂ - Ф₁) 
     H = 319.5 x 4.186 x (100 - 35.7) = 85996.56J
Now; 
      1kilocalorie = 4184J
       
85996.56J to kCal; 
   = 20.6kCal  = 20600Cal
                 
learn more: 
Specific heat brainly.com/question/3032746
#learnwithBrainly
 
        
             
        
        
        
The air pressure inside the can is lower compared to that of outside air pressure.
Explanation:
- In general, the air pressure of an already opened can will be the same as the outside pressure.
 - Since the can is evacuated and remain as vacuum, so there will be no pressure difference in it.
 - If the can opens, air inside the can push the top and escapes to the outside.
 - This is due to high pressure experienced outside the can compare to that of lower pressure inside the can and this may even cause can to collapse itself.
 
 
        
             
        
        
        
This statement would be best characterized by the law of conservation of momentum—choice C.