- Introduction
- Learn
Try It- Task
Try It
For this Try It, you will be drawing force diagrams illustrating several different scenarios. Draw a diagram in your notebook and then move to the next tab to check your answer.
Example 1
Draw a force diagram that illustrates the following:
Sarah is in her car coasting to the right and slowing down.
Example 1 Answer
Example 1: Sarah is in her car coasting to the right and slowing down.
Answer 1:
- The car is coasting; therefore, there is zero acceleration.
- Since the car is moving, the friction force (Ff) is opposing the motion.
- The car is sitting on the road/ground. Therefore, the car applies a force toward the ground (Fg), and the ground applies a force upward (FN).
Example 2
Draw a force diagram that illustrates the following:
After Tyler kicks a football, it moves upwards towards its peak.
Example 2 Answer
Example 2: After Tyler kicks a football, it moves upwards towards its peak.
Answer:
- Once the football leaves his foot, the only force acting on the football is gravity.
- An object must be in contact with other objects in order for any other forces (except gravity) to act on them.
Example 3
Draw a force diagram that illustrates the following:
John pulls a sled to the right across loosely packed snow with a rightward acceleration.
Example 3 Answer
Example 3: John pulls a sled to the right across loosely packed snow with a rightward acceleration.
Answer:
- Since the sled is accelerating, the vector (arrow length) of the applied force (Fa) is longer than the arrow representing the opposing force, the friction force (Ff). It is longer to indicate that the magnitude of the applied force is greater.
- The sled is sitting on the ground; therefore, the car applies a force toward the ground (Fg), and the ground applies a force upward (FN).
Example 4
Draw a force diagram that illustrates the following:
Jennifer's backpack is suspended motionless by one strap on her shoulder.
Example 4 Answer
Example 4: Jennifer's backpack is suspended motionless by one strap on her shoulder.
Answer:
- The backpack is hanging from Jennifer's shoulder by one strap. When objects are being pulled, we call it tension force (Ft). There is tension on the strap of the backpack.
- The force of gravity is directed toward the ground.
- Since the object is suspended, there is no normal force.
