Why is it necessary to review job trends while making a career plan?

Career planning is important for a number of reasons - having a career development plan in place reduces your risk of making impulsive decisions, and helps you recognise when you're ready to look for new opportunities and develop new skills.

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.