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:
Answer:
Explanation:
A magnet has a magnetic field around it which originates at the north pole and enters through the south pole.
In a magnet, like poles will repel each other and unlike poles will attract.
- The north pole of one magnet will repel another north pole of another magnet.
- North pole of one magnet will attract the south pole of another magnet.
- This is the law of attraction and repulsion of magnet.
Answer:
225 rpm
Explanation:
The angular acceleration of the fan is given by:

where
is the final angular speed
is the initial angular speed
is the time interval
For the fan in this problem,

Substituting,

Now we can find the angular speed of the fan at the end of the 5th second, so after t = 5 s. It is given by:

where

Substituting,

Answer:
all I know is C
are there more questions? anyone?
-KARL IS STOOPID
Explanation:
To determine the amount in grams of the iron, we need data on the density of iron. From literature, it has a value of <span>p=7.9 g/cm3. We simply multiply the volume to the density. We do as follows:
mass = 3.70 (7.9) = 29.23 g Fe
Hope this answers the question. Have a nice day.</span>