Download - Free-body diagrams
![Page 1: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/1.jpg)
Free-body diagramsFree-body diagrams
Free-body diagrams are used to show the relative magnitude and direction of all forces acting on an object.
![Page 2: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/2.jpg)
This diagram shows four forces acting upon an object. There aren’t always four forces, For example, there could be one, two, or three forces.
![Page 3: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/3.jpg)
Problem 1Problem 1
A book is at rest on a table top. Diagram the forces acting on the book.
![Page 4: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/4.jpg)
Problem 1Problem 1
In this diagram, there are normal and gravitational forces on the book.
![Page 5: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/5.jpg)
Problem 2Problem 2
An egg is free-falling from a nest in a tree. Neglect air resistance. Draw a free-body diagram showing the forces involved.
![Page 6: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/6.jpg)
Gravity is the only force acting on the egg as it falls.
![Page 7: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/7.jpg)
Problem 3Problem 3
A flying squirrel is gliding (no wing flaps) from a tree to the ground at constant velocity. Consider air resistance. A free body diagram for this situation looks like…
![Page 8: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/8.jpg)
Gravity pulls down on the squirrel while air resistance keeps the squirrel in the air for a while.
![Page 9: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/9.jpg)
Problem 4Problem 4
A rightward force is applied to a book in order to move it across a desk. Consider frictional forces. Neglect air resistance. Construct a free-body diagram. Let’s see what this one looks like.
![Page 10: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/10.jpg)
Note the applied force arrow pointing to the right. Notice how friction force points in the opposite direction. Finally, there is still gravity and normal forces involved.
![Page 11: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/11.jpg)
Problem 5Problem 5
A car runs out of gas and is coasting down a hill.
![Page 12: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/12.jpg)
Even though the car is coasting down the hill, there is still the dragging friction of the road (left pointing arrow) as well as gravity and normal forces.
![Page 13: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/13.jpg)
Sitting Gorilla
Free Body Diagram of the Sitting Gorilla (The box represents the gorilla, W = weight of the gorilla,
N = Normal force)
W
N
Create a free body diagram (FBD) for each of the following situations. Draw a FBD of the gorilla:
![Page 14: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/14.jpg)
This is also an acceptable diagram.
N
W
Sitting Gorilla
Create a free body diagram (FBD) for each of the following situations. Draw a FBD of the gorilla:
![Page 15: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/15.jpg)
Parrot on wooden swing hung by ropes
Draw a FBD of the wooden swing:
Free Body Diagram of the wooden swing (The box represents the wooden swing, W = weight of the swing and the parrot, T represents the ropes that are in tension supporting the weight)
W
T2T1
![Page 16: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/16.jpg)
Bungee jumping from crane
Draw a FBD of bucket the bungee jumper leaped from:
Free Body Diagram of the bucket (T
represents the tensile force of the cable the bucket is suspended from, and W is the weight of the diver and the bucket)
W
T
![Page 17: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/17.jpg)
Traffic Light supported by cables
Draw a FBD of the ring at point C:
A B
C
D
Free Body Diagram of the ring at point C (T represents the force of the cables that are in tension acting on the ring)
TCD
TCATCB
![Page 18: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/18.jpg)
Draw a FBD of the traffic light:
Free Body Diagram of the traffic light (TCD represents the force of the cables acting on the light and W is the weight acting on the light)
W
TCD
Traffic Light supported by cables
A B
C
D
![Page 19: Free-body diagrams](https://reader033.vdocuments.us/reader033/viewer/2022061606/56815a2a550346895dc76cb9/html5/thumbnails/19.jpg)
Pin-Connected Pratt Through Truss Bridge
Draw a FBD of the pin at point A:
A B
ED
CFree Body Diagram of pin A
(If you consider the third dimension, then there is an additional force acting on point A into the paper: The force of the beam that
connects the front of the bridge to the back of the bridge.)
TAETAC
TAB
TAD