Answer:
Acceleration will be  
                     
Explanation:
We have given that car is traveling with speed 34 miles per hour 
So initial speed of the car u = 34 miles per hour 
After 2 hour speed will be 84 miles per hour 
So final speed V = 84 miles per hour 
Time = 2 hour 
From first equation of motion we know that 
So acceleration 
 
        
             
        
        
        
Answer:
   2
Explanation:
If the energy is doubled, the mass must be doubled (increased by a factor of 2) in order for the temperature effect to remain the same.
Heat capacity is measured in units of J/(kg·°C), so the ratio will remain constant if mass varies directly with amount of heat.