#1 is sand dune , #2 glaciers , #3 sand sediments hence small mass and #4 is <span> moraine .</span>
Answer;
a. shorten the focal length of the lens.
Explanation;
-Magnification is the ratio of the image height to the object height, which is closely related to the ratio of the image distance to the object distance. A magnifying glass is a convex lens that is used to produce a magnified image of an object. Magnifying power is how much larger a given lens can make an image appear. This is a direct relationship between the focal length of the lens and the least distance of distinct vision
-Shortening the focal length of the lens increases the magnification of an image with a magnifying glass.
Given,
Effort force = 120 N
Load force= 1050 N
Mechanical advantage of a pulley is given by the ratio of load force to the effort force.
![M.A=\frac{Load force}{Effort force}](https://tex.z-dn.net/?f=%20M.A%3D%5Cfrac%7BLoad%20force%7D%7BEffort%20force%7D%20%20)
![=\frac{1050}{120}](https://tex.z-dn.net/?f=%20%3D%5Cfrac%7B1050%7D%7B120%7D%20%20)
![=8.75](https://tex.z-dn.net/?f=%20%3D8.75%20)
Therefore, the mechanical advantage of the given pulley is 8.75.