4. Determine the percent composition in each element of Mg3(PO4)2. Show your work

Here's link to the

cutt.ly/zxt1ipy

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.