<span>12-50t=70t, t= 0.1h = 6 minutes.</span>
Complete Question
The distance between the objective and eyepiece lenses in a microscope is 19 cm . The objective lens has a focal length of 5.5 mm .
What eyepiece focal length will give the microscope an overall angular magnification of 300?
Answer:
The eyepiece focal length is
Explanation:
From the question we are told that
The focal length is 
This negative sign shows the the microscope is diverging light
The angular magnification is 
The distance between the objective and the eyepieces lenses is 
Generally the magnification is mathematically represented as
![m = [\frac{Z - f_e }{f_e}] [\frac{0.25}{f_0} ]](https://tex.z-dn.net/?f=m%20%20%3D%20%20%5B%5Cfrac%7BZ%20-%20f_e%20%7D%7Bf_e%7D%5D%20%5B%5Cfrac%7B0.25%7D%7Bf_0%7D%20%5D)
Where
is the eyepiece focal length of the microscope
Now making
the subject of the formula
![f_e = \frac{Z}{1 - [\frac{M * f_o }{0.25}] }](https://tex.z-dn.net/?f=f_e%20%20%3D%20%5Cfrac%7BZ%7D%7B1%20-%20%5B%5Cfrac%7BM%20%20%2A%20%20f_o%20%7D%7B0.25%7D%5D%20%7D)
substituting values
![f_e = \frac{ 0.19 }{1 - [\frac{300 * -0.0055 }{0.25}] }](https://tex.z-dn.net/?f=f_e%20%20%3D%20%5Cfrac%7B%200.19%20%7D%7B1%20-%20%5B%5Cfrac%7B300%20%20%2A%20%20-0.0055%20%7D%7B0.25%7D%5D%20%7D)
As we know that in transformers we have

here we know that




now from above equation we will have


now we have to reduce this voltage to final voltage of V = 4 V
so again we will have



so we need to take such a winding whose ratio is 1:5
So it is satisfied in X


so answer will be
<u>B)- X</u>
Answer:

Explanation:
<u>Sum of Vectors in the Plane</u>
Given two vectors

They can be expressed in their rectangular components as


The sum of both vectors can be done by adding individually its components

If the vectors are given as a magnitude and an angle
, each component can be found as


The first vector has a magnitude of 3.14 m and an angle of 30°, so


The second vector has a magnitude of 2.71 m and an angle of -60°, so


The sum of the vectors is


Finally, we compute the magnitude of the sum



If the boy outputs enough weight upon the ball in response the ball will move.
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