Which of the following microscope parts should routinely be adjusted to control the light source and provide optimal illuminatio
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<h2>Answer:</h2>
(a) 10N
<h2>Explanation:</h2>The sketch of the two cases has been attached to this response.
<em>Case 1: The box is pushed by a horizontal force F making it to move with constant velocity.</em>
In this case, a frictional force is opposing the movement of the box. As shown in the diagram, it can be deduced from Newton's law of motion that;
∑F = ma -------------------(i)
Where;
∑F = effective force acting on the object (box)
m = mass of the object
a = acceleration of the object
∑F = F -
m = 50kg
a = 0 [At constant velocity, acceleration is zero]
<em>Substitute these values into equation (i) as follows;</em>
F - = m x a
F - = 50 x 0
F - = 0
F = -------------------(ii)
<em>Case 2: The box is pushed by a horizontal force 1.5F making it to move with a constant velocity of 0.1m/s²</em>
In this case, the same frictional force is opposing the movement of the box.
∑F = 1.5F -
m = 50kg
a = 0.1m/s²
<em>Substitute these values into equation (i) as follows;</em>
1.5F - = m x a
1.5F - = 50 x 0.1
1.5F - = 5 ---------------------(iii)
<em>Substitute </em><em> = F from equation (ii) into equation (iii) as follows;</em>
1.5F - F = 5
0.5F = 5
F = 5 / 0.5
F = 10N
Therefore, the value of F is 10N
<em />
Answer:
58.27 N
Explanation:
the data we have is:
mass:
coefficient of friction:
and we also know the acceleration of gravity is
We need to do an analysis of horizontal and vertical forces acting on the object:
-------
Vertically the forces acting on the object:
- Normal force
(acting up from the object)
- weight:
(acting down from)
so the sum of forces in the vertical axis "y" are:
from Newton's second Law we know that , so:
and since the object is not accelerating in the vertical direction (the movement is only horizontal) , and:
-----------
now let's analyze the horizontal forces
- frictional force:
and since
-->
- force to move the object:
and the two forces just mentioned must be opposite, thus the sum of forces in the "x" axis is:
and we are told that the crate moves at a steady speed, thus there is no acceleration:
and we get:
substituting known values: