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:
η = 40 %
Explanation:
Given that
Qa ,Heat addition= 1000 J
Qr,Heat rejection= 600 J
Work done ,W= 400 J
We know that ,efficiency of a engine given as

Now by putting the values in the above equation ,then we get

η = 0.4
The efficiency in percentage is given as
η = 0.4 x 100 %
η = 40 %
Therefore the answer will be 40%.
Answer:
-26 m/s.
Explanation:
Hello,
In this case, since the vertical initial velocity is 26 m/s and the vertical final velocity is 0 m/s at P, we compute the time to reach P:

With which we compute the maximum height:

Therefore, the final velocity until the floor, assuming P as the starting point (Voy=0m/s), turns out:

Which is clearly negative since it the projectile is moving downwards the starting point.
Regards.
Answer: feet first
Explanation:
It is always the safest to enter with your feet first. You can become paralyzed or injure you neck if you dive into a body of water that is too shallow. Therefore its always best to dive feet first instead.