1 / 12

Motion & Forces

Motion & Forces . Chapter 11.3 Pages 380 - 385. Force. Any action that can change the state of motion of an object. Four Fundamental Forces. Force of gravity – example: Earth’s pull on all objects on it. Electromagnetic force – example: force produced by electricity

tacy
Download Presentation

Motion & Forces

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Motion & Forces Chapter 11.3 Pages 380 - 385

  2. Force • Any action that can change the state of motion of an object

  3. Four Fundamental Forces • Force of gravity – example: Earth’s pull on all objects on it. • Electromagnetic force – example: force produced by electricity • Strong nuclear force – force that keeps protons in the nucleus together • Weak nuclear force – observed during radioactive decay

  4. Net Force • Total Force on an object

  5. Calculating Net Force • If forces act in the same direction on an object, you need to add the forces. • If forces act in opposite directions on an object, you need to subtract the forces.

  6. Balanced Forces • Forces are balanced if the net force is equal to zero. • The object must be at rest or moving at a constant velocity.

  7. Unbalanced Forces • Forces are unbalanced if the net force is not zero. • The object must be accelerating.

  8. Practice Problems: • Barry pushes a desk to the right with a force of 250 N as Jenna helps him push it to the right with a force of 325 N. What is the net force on the desk? In what direction? Are the forces balanced or unbalanced? Is the desk accelerating? Answer: 250 N + 325 N = 575 N to the right The forces are unbalanced The desk is accelerating

  9. Practice Problems: 2. Carrie pulls a book east towards her with a force of 65 N while Martha pulls the book west towards her with a force of 55 N. What is the net force on the book? In what direction? Are the forces balanced or unbalanced? Is the book accelerating? Answer: 65 N - 55 N = 10 N to the east The forces are unbalanced The book is accelerating

  10. Practice Problems: 3. Kathy and Beth are arguing where their sofa should go. Kathy pushes the sofa to the right with a force of 175 N while Beth pushes it to the left with a force of 175 N. What is the net force on the desk? In what direction? Are the forces balanced or unbalanced? Is the desk accelerating? Answer: 175 N - 175 N = 0 N, no direction The forces are balanced The desk is not accelerating

  11. Practice Problems: 4. Two students pushes a heavy crate each with a force of 225 N north while one student pushes it south with a force of 300 N. What is the net force on the crate? In what direction? Are the forces balanced or unbalanced? Is the crate accelerating? Answer: (225 N x 2) – 300 N 450 N – 300 N = 150 N, north The forces are unbalanced The crate is accelerating

  12. Practice Problems: 5. The force of gravity is pulling a pail of water downward with a force of 50 N while a rope is holding it up with a force of 50 N. What is the net force on the pail? In what direction? Are the forces balanced or unbalanced? Is the pail accelerating? Answer: 50 N – 50 N = 0 N, no direction The forces are balanced The crate is not accelerating

More Related