Answer:
The position is 8.18cm from the mirror.
Nature is b=virtual
Size is 1.82cm
Explanation:
Note that for a convex mirror, the image distance and the focal length are negative;
Given
Object height H0 = 4cm
object distance u = 18cm
Radius of curvature R = 30cm
Since f = R/2
f = 30/2
f = -15cm
Recall that:

Since the image distance is negative, this shows that the image is a virtual image.
To get the size:

Well, that would be a plane (flat) mirror
<span>provided that </span>
<span>the mirror and the object are oriented parallel to each other</span>
just swim In water and find your shoe
They are dynamic, with winds and waves constantly reworking and moving
the barrier island sand.
Changes in sea level also affect these islands.
Most scientists agree that sea level has been gradually rising over the
last thousand years, and this rise could be accelerating today due to global warming.
Rising sea level causes existing islands to migrate shoreward.