please help me please

Question

A 75N sack is dragged along the floor with a horizontal force of 100N to the right. The frictional force is 30N. The free body diagram will help you answer the questions that follow. 

What letter represents Fg, and what is its value?

Answer 1

The free body diagram was left out. However, F_g represents force due to gravity. This will always be a force directed straight down on a free body diagram. The magnitude of F_g = weight (w) = mg and is measured in Newtons. The problem gives the following components:

1. w = 75 N
2. F_applied = 100 N to the right
3. F_friction = 30 N to the left

We can conclude that the arrow representing F_g is the one pointing straight down and the magnitude of F_g is 75 N.