Explanation:
The reading on the scale is
W = m(g + a)
 = (77 kg)(9.8 m/s^2 + 2 m/s^2)
 = 908.6 N
 
        
             
        
        
        
Let say the two train cars are of masses  and
 and 
now if the speed of two cars are  and
 and 
then we can say that the momentum of two cars before they collide is given by

here two cars are moving in opposite direction so we can say that the net momentum is subtraction of two cars momentum.
Now since in these two car motion there is no external force on them while they collide
So the momentum of two cars are always conserved.
hence we can say that the final momentum of two cars will be same after collision as it is before collision

 
        
                    
             
        
        
        
Answer:
I believe it might be point A since the question ask what will result in the ln a largest increase in potential energy
Explanation:
 
        
             
        
        
        
Answer: The first one
Explanation: I think it's the first one because it says what is the "least" gravitational potential energy story between the prairie dog and Earth that said resting in its borrow is using less energy 
 
        
                    
             
        
        
        
First, we assume this as an ideal gas so we use the equation PV=nRT. Then, we use the conditions at STP that would be 1 atm and 273.15 K. We calculate as follows:
PV= nRT
PV= mRT/MM
1 atm (.245 L) =1.30(0.08206)(273.15) / MM
MM = 118.94 g/mol <--- ANSWER