Free-Body (Force) Diagrams
1. A book is at rest on a table top. Diagram the forces acting on the book.
2. An egg is free-falling from a nest in a tree. Neglect air resistance. Diagram the forces acting
on the egg as it falls.
3. A piece of paper is falling to the ground at constant velocity. Consider air resistance.
Diagram the forces acting on the paper.
4. A rightward force is applied to a book in order to move it across a desk with a rightward
acceleration. Consider frictional forces. Neglect air resistance. Diagram the forces acting on the
book.
5. A rightward force is applied to a book in order to move it across a desk at constant velocity.
Consider frictional forces. Neglect air resistance. Diagram the forces acting on the book.
6. A college student rests a backpack upon his shoulder. The pack is suspended motionless by
one strap from one shoulder. Diagram the vertical forces acting on the backpack.
7. A skydiver is descending with a constant velocity. Consider air resistance. Diagram the
forces acting upon the skydiver.
8. A force is applied to the right to drag a sled across loosely-packed snow with a rightward
acceleration. Diagram the forces acting upon the sled.
9. A football is moving upwards towards its peak after having been booted by the punter.
Neglect air resistance. Diagram the forces acting upon the football as it rises upward towards
its peak. (Not while being kicked)
10. A car is coasting to the right and slowing down. Diagram the forces acting upon the car.
11. Write a problem or a story for the following Free-body diagrams and identify the direction of
acceleration or if the acceleration is equal to zero m/s2.
Net Force
12. Directions: For Situations A-D determine the net force acting on the object in the x direction
and y direction.
13. Directions: Determine the missing forces from each of the diagrams below.
1. A =
2. C =
3. D =
4. F =
E=
G=
B=
H=
For numbers 1-4 above, which direction (up, down, left, right) would each of the objects accelerate.
1.
2.
3.
4.
Mixed Practice:
1. What is a force and how does it affect the motion of an object?
2. If the forces acting on an object are 50N in one direction and 30N in the other direction, what is the net
force acting on the object?
3. Draw a free-body diagram for a book with horizontal forces of 20N and -10N acting upon it. What is the
net force acting on the book?
4. A book has an acceleration of -2m/s2 and 1 horizontal force acting on it. 2 vertical forces act on it and the
net force in the vertical direction is zero. Draw a free-body diagram for the situation.
5. A rightward force is applied to a rolling chair to move it across the floor at a constant velocity. Draw a
free-body diagram for the situation.
6. In question number 5, what is the net force in the vertical direction?
What is the net force in the horizontal direction?
7. A force of 7N is applied to a box while the force of friction is 3N. The weight of the box is 4N as is the
normal force. Draw a free-body diagram. Determine the net force acting on the box and label the direction
of the acceleration.
8. The net force acting on a 140N desk is 40N, right. (Hint: 140 N is the weight of the desk.) The frictional
force is 20 N. What is the force applied to the desk? Draw and label a free-body diagram to assist you.