Answer:
-78.4 cm
Explanation:
We can solve the problem by using the lens equation:

where
p is the distance of the object from the lens
q is the distance of the image from the lens
f is the focal length
Here we have
p = 80.0 cm
q = -39.6 cm (negative, because the image is on the same side as the object , so it is a virtual image)
Substituting, we find f:


Answer:
<h2>The answer is 4 s</h2>
Explanation:
The time taken can be found by using the formula

where
d is the distance
v is the velocity
From the question we have

We have the final answer as
<h3>4 s</h3>
Hope this helps you
In the first shell there can be a maximum of 2 electrons, then 8o in the second one and 8 in the third one.