Answer:
Wave A
<em>I</em><em> </em><em>hope this</em><em> </em><em>helps</em><em> </em>
The work W done by the electric field in moving the proton is equal to the difference in electric potential energy of the proton between its initial location and its final location, therefore:

where q is the charge of the proton,

, with

being the elementary charge, and

and

are the initial and final voltage.
Substituting, we get (in electronvolts):

and in Joule:
Answer:
the energy of the spring at the start is 400 J.
Explanation:
Given;
mass of the box, m = 8.0 kg
final speed of the box, v = 10 m/s
Apply the principle of conservation of energy to determine the energy of the spring at the start;
Final Kinetic energy of the box = initial elastic potential energy of the spring
K.E = Ux
¹/₂mv² = Ux
¹/₂ x 8 x 10² = Ux
400 J = Ux
Therefore, the energy of the spring at the start is 400 J.
If it's not moving at all at the beginning of the 10 seconds, then it falls 490 meters straight down in 10 seconds.
(Note: This is true of all objects on Earth . . . rubber balls, feathers, grains of sand, school buses, battle ships . . . everything. As long as air doesn't hold them back. Anything falling from rest falls 490 meters in the first 10 seconds.)