The height, h to which the package of mass m bounces to depends on its initial velocity, v and the acceleration due to gravity, g and is given below:

<h3>What are perfectly elastic collision?</h3>
Perfectly elastic collisions are collisions in which the momentum as well as the energy of the colliding bodies is conserved. 
In perfectly elastic collisions, the sum of momentum before collision is equal to the momentum after collision.
Also, the sum of kinetic energy before collision is equal to the sum of kinetic energy after collision.
Since some of the Kinetic energy is converted to potential energy of the body;


Therefore, the height to which the package m bounces to depends on its initial velocity and the acceleration due to gravity. 
Learn more about elastic collisions at: brainly.com/question/7694106
 
        
             
        
        
        
Answer:
constant velocity unless acted on my an opposite force 
 
        
             
        
        
        
Answer:
B and C
Explanation:
Because EMWs are varying magnetic and electric radiation traveling at 90° to each other propagating energy form one place to another through vibration of these magnetic and electric fields
 
        
             
        
        
        
Answer:
No
Explanation:
20 billion light-years away are beyond our sight and perspective on Earth and wouldn't be observable in our universe.