Question

Problems 35 through 40 show a free-body diagram. For each:

a. Identify the direction of the acceleration vector au and show it as a vector next to your diagram. Or, if appropriate, write$\overrightarrow{a}=\overrightarrow{0}$

b. If possible, identify the direction of the velocity vector $\overrightarrow{v}$and show it as a labeled vector.

c. Write a short description of a real object for which this is the

correct free-body diagram. Use Examples 5.4, 5.5, and 5.6 as

models of what a description should be like.

Short answer

Free-body diagram of an object such as bullock cart is given here that is been dragged along negative x-axis.

Step-by-step solution

Part a Step 1: Identifying the acceleration vector

According to the given diagram, there is a non-zero net force along negative x-axis. So, the direction of acceleration vector should be directed from left to right.

Labelling the acceleration vector

The acceleration vector $\overrightarrow{a}$is shown in the given diagram:

Part b Step 1: Identifying the velocity vector

• The free-body diagram shows, there is a kinetic friction that is working on the object that indicates there must be a non-zero velocity.
• The net force is along right to left concludes that the velocity vector should be directed towards negative x-axis.

Labelling the velocity vector 

The velocity vector is labelled in the free body diagram given below:

Part c Step 1: Explanation of the body diagram

• According to the given body diagram, the normal force $\overrightarrow{n}$and gravitational force ${\overrightarrow{F}}_G$acting on the object are equal and directed in opposite directions.
• Therefore, the object should be in balanced condition in vertical direction or lies in a horizontal surface.
• The object is being pulled to the left with a nonzero net force, so it is accelerating to the left.
• A kinetic friction force is acting along positive x-axis. So, there is a nonzero velocity of the object along negative x-axis where a net force is directed along.

Description of a real object

The free-body diagram states that an object for example a bullock cart is been pulled out through a muddy road. So, there is a tension force by the rope with which the cart is dragged out acts on the cart and the cart is accelerating from right to left.