1 / 19

Mass and Acceleration

Mass and Acceleration. f. N. T. M. W. Types of Forces. Noncontact Forces. Contact Forces. Gravitational. Electromagnetic. Nuclear. Pushes. Pulls. Tension. Friction. Normal. Electric. Magnetic. perpendicular to surface. Newton’s 1 st Law:. No net force - no acceleration

fiona-cash
Download Presentation

Mass and Acceleration

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. Mass and Acceleration

  2. f N T M W Types of Forces Noncontact Forces Contact Forces Gravitational Electromagnetic Nuclear Pushes Pulls Tension Friction Normal Electric Magnetic perpendicular to surface

  3. Newton’s 1st Law: • No net force - no acceleration • No acceleration = constant velocity

  4. Dry Ice on Slate Motion of the Block Velocity Acceleration Push or Pull Necessary to Maintain Motion 0 0 0 at rest uniform motion to the right 0 0 moves to the right and speeds up without changing direction moves to the right, slows down and stops without changing direction

  5. Fby snow Fby gravity Pretest #3(“the crate in the snow”) ?

  6. Fby snow Fby gravity Pretest #3(“the crate in the snow”)

  7. Nr,b Fnet a a Nr,b WE,b WE,b Newton’s 2nd Law: • Net force causes acceleration (not velocity) • The net force is the vector sum of all the individual forces on an object. Acceleration is in same direction as the net force.

  8. f N T M W Which one is the net force? Types of Forces Noncontact Forces Contact Forces Gravitational Electromagnetic Nuclear Pushes Pulls Tension Friction Normal Electric Magnetic

  9. What’s the mass? • A measure of “how much stuff” • A measure of how hard it is to speed up or slow down • Very different than weight!

  10. Hammer of Death

  11. F a Fnet a F  a More net force - more acceleration(constant mass)

  12. F 1  M a a F a More mass - less acceleration(constant net force)

  13. M Fnet Fnet Fnet  Constant × a a a M  M Putting it all together Newton is defined such that constant = 1.

  14. Scale reading = ? 10 N 1.0 kg

  15. Scale reading = ? 10 N 20 N 2.0 kg

  16. Free body diagram of 1 kg crate: TS,C (Reading on the scale) WE,C

  17. In General • The force that the Earth exerts on an object of mass m is given byW = m (10 N/kg)

  18. WE,J W = m (10 N/kg) Question: = m g • If Jeff jumps off the physics building in a vacuum, what will his acceleration be? (use Newton’s 2nd law) Fnet = m a WE,J = m a m (10 N/kg)= m a 10 N/kg is just g Weight force is given by mg

  19. a = 4 m/s/s a = 4 m/s/s Nfloor,B T = 100 N M = 5 kg ffloor,B In the x-direction: Trope,B = 100 N Block Fnet = m a T - f = m a WE,B 2nd Law is the translator How big is the friction force? = 50 N = 80 N 100 N - f = (5 kg) (4 m/s/s) = m g = 50 N f = 80 N

More Related