Question

Exercises 21 show a free-body diagram. Write a short description of a real object for which this would be the correct free-body diagram. Use Examples 5.4, 5.5, and 5.6 as examples of what a description should be like.

Short answer

The free body diagram is a pictorial representation of an object under some forces where the object acts as an particle and the forces acting on the object.

Step-by-step solution

Given information:

The object is represented by the dot according to the particle model.

The drag force F_drag and the force due to gravity F_G is acting downward along the negative Y-axis with F_G > F_drag.

The thrust is acting upward along the positive Y-axis.

The net force is drawn beside the diagram which is acting upwards.

Writing the description of real object that explains the given free body diagram:

Example 5.3 is a suitable example for the given free body diagram which states

"A rocket is launched vertically"

The rocket is considered as the particle here.

Since the net force is acting upward,

$F_{net}=F_{thrust}-\left(F_G+F_{drag}\right)$

The thrust is due to the engine of the rocket, force of gravity is due to its mass and drag force is due to the air resistance.