Estimate the surface area of the rectangular prism.

28 cm^2

Step-by-step explanation:

First we will find the area of the top and bottom rectangles.

They have side lenghts of 2 and 1. So the area of 1, after multipying 2 and 1 is 2.

So the area of 2 is 4 cm^2.

Next we will find the area of the front and back rectangles.

They have side lenghts of 4 and 2cm.

So after multiplying them and adding both products we get 16 cm ^2.

Now for the left and right.

The side lenghts for those two are 4 and 1 cm.

So after multiplying them and adding the products we get 8 cm ^2.

So after adding all the areas we get 28 cm^2.

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.