1) Focal length
We can find the focal length of the mirror by using the mirror equation:

(1)
where
f is the focal length

is the distance of the object from the mirror

is the distance of the image from the mirror
In this case,

, while

(the distance of the image should be taken as negative, because the image is to the right (behind) of the mirror, so it is virtual). If we use these data inside (1), we find the focal length of the mirror:

from which we find

2) The mirror is convex: in fact, for the sign convention, a concave mirror has positive focal length while a convex mirror has negative focal length. In this case, the focal length is negative, so the mirror is convex.
3) The image is virtual, because it is behind the mirror and in fact we have taken its distance from the mirror as negative.
4) The radius of curvature of a mirror is twice its focal length, so for the mirror in our problem the radius of curvature is:
Light striking the walls of the glass cylinder and reflecting in inside tube itself is a phenomenon known as total internal reflection.
<h3>What word best describes reflection, in your opinion?</h3>
Reflection is often synonymous with the verbs cogitate, contemplate, reason, hypothesize, and think. All of these expressions mean "using one's intellect, judgment, or inference faculties," but the word "reflect" means carefully considering a recollection.
<h3>What does it mean to give reflection some thought?</h3>
constant verb When you ruminate, you seriously consider something. Alternatives include thinking, analyzing, planning, and thinking. More phrases containing "reflect" Reflecting feelings is the act of observing a person's verbal and nonverbal signs for their emotions and feelings, then immediately communicating (or reflecting) those attitudes to the user or customer.
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Answer:
I believe that the answer is d.
Explanation:
Because there is nothing to make the aircraft accelerate or decelerate, it is going to stay in constant motion with no acceleration.
A) The resultant force is 30.4 N at 
B) The resultant force is 18.7 N at 
Explanation:
A)
In order to find the resultant of the two forces, we must resolve each force along the x- and y- direction, and then add the components along each direction to find the components of the resultant.
The two forces are:
at
above x-axis
at
above y-axis
Resolving each force:


So, the components of the resultant are:

And the magnitude of the resultant is:

And the direction is:

B)
In this case, the 15 N is applied in the opposite direction to the 20 N force. Therefore we need to re-calculate its components, keeping in mind that the angle of the 15 N force this time is

So we have:

So, the components of the resultant this time are:

And the magnitude is:

And the direction is:

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Explanation:
It is given that,
Length of the helicopter, l = 3.1 m
The helicopter rotates, the length of helicopter will become the radius of circular path, r = 3.1 m
Angular speed of the helicopter, 
(a) The centripetal acceleration in terms of angular velocity is given by :



(b) Let v is the linear speed of the tip. The relation between the linear and angular speed is given by :


v = 90.89 m/s

Hence, this is the required solution.