Elastic potential energy is kind of like pulling on something and then letting it go, with rubber bands, or a bow, or a slingshot, something with elastic properties. 
Gravitational potential energy has to do with how high something is, and has to do with earth’s gravitational pull.
        
                    
             
        
        
        
Answer:
0.3956
Explanation:
Newton's 2nd law of motion says that Force = Mass*Acceleration (f=ma) so to find the force used on the football you multiply it's mass by its acceleration. 
0.43*0.92 = 0.3956.
0.4 if you round
 
        
             
        
        
        
Newton´s thrid law of motion states that:
Every action has an equal and opposite reaction.
c. equal, opposite. 
        
             
        
        
        
Answer:
Radius of the solenoid is 0.93 meters.
Explanation:
It is given that,
The magnetic field strength within the solenoid is given by the equation,
, t is time in seconds

The induced electric field outside the solenoid is 1.1 V/m at a distance of 2.0 m from the axis of the solenoid, x = 2 m
The electric field due to changing magnetic field is given by :

x is the distance from the axis of the solenoid
, r is the radius of the solenoid


r = 0.93 meters
So, the radius of the solenoid is 0.93 meters. Hence, this is the required solution.
 
        
                    
             
        
        
        
Answer:
First law of thermodynamic state that energy is always conserved, in other word, energy cannot be created or destroyed.
This means that energy can only transfer from one source to another.
For example, the electricity we used to power our phone didn't come from nowhere. 
We charge our phone using the energy from the electricity from the outlet.
The outlet gets its energy from the power plant, who generated that energy from burning coal.
The coal they burned got their energy while they were alive as plants.
The plants got their energy from the sun.
The sun got its energy from other cosmic stuff and so on...
My point is that the energy we use will always cycle around. It doesn't come from thin air and it doesn't disappear into thin air either. This help keeps things balance because if energy is created out of thin air then the earth might just blow up. If energy gets erased into thin air then there'll be nothing to fuel life.