forces n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Forces PowerPoint Presentation
Download Presentation
Forces

Loading in 2 Seconds...

play fullscreen
1 / 8

Forces - PowerPoint PPT Presentation


  • 117 Views
  • Uploaded on

Forces. Summarizing a few things we know…. From the Bowling Ball and Air Track activities we have evidence that…. Forces are responsible for changes in motion F same direction as v : Speed up F opposite direction as v : slow down F perpendicular to v : changing direction

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Forces' - jolie-davidson


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
forces

Forces

Summarizing a few things we know…

from the bowling ball and air track activities we have evidence that
From the Bowling Ball and Air Track activities we have evidence that…
  • Forces are responsible for changes in motion
    • F same direction as v: Speed up
    • F opposite direction as v: slow down
    • F perpendicular to v: changing direction
    • Forces cause acceleration
  • When there is no netforce, motion does not change in any way… a = 0 m/s2
from the force probe demos with cam and george we have evidence that
From the Force Probe demos (with Cam and George) we have evidence that…
  • Forces can only exist in pairs
  • Action-Reaction forces are always equal in size
  • Action-reaction forces are always opposite in direction
  • Action-reaction forces always act on different objects (forces are an interaction between two things)
  • If A pulls/pushes B, then B pulls/pushes A equally in the other direction
from the force of the earth activity we have evidence that
From the Force of the Earth activity we have evidence that…
  • The force the earth on an object is directly proportional to the mass of the object.

Fearth = (10 N/kg)m

      • The intercept is zero…zero mass feels no force from earth
      • The slope is called the gravitational field strength, g
          • All objects in the same location experience the same gravitational field strength
      • The “force of the earth” on an object is more commonly know as the object’s weight

Fearth

(N)

m (kg)

mass vs weight
Mass vs. Weight
  • Mass – a measure of the quantity of matter in an object, a property of the object, NOT a force.
      • This value is the same regardless of location
      • A measure of an object’s inertia
      • SI unit is the kilogram (kg)
  • Weight – a measure of the force of gravity on an object.
      • This value depends on the object’s location in a gravitational field.
      • SI unit is the Newton (N)
      • Weight = mass x gravitational field strength

Fg = mg

*Near the surface of Earth, a 1 kg mass weighs 10 N

equilibrium a condition of balance
Equilibrium-a condition of balance
  • We were able to measure the weight of the objects using a scale because they were in equilibrium.

Since acceleration = 0 m/s2, the forces must be balanced, thus the reading on the scale was equal to the weight

Force from the scale

Force from the earth…weight

equilibrium
Equilibrium
  • Static equilibrium
    • Object at rest
  • Dynamic equilibrium
    • Object moving at constant speed
  • True for both…
  • Acceleration = zero (a = 0 m/s2)
  • Net force = zero (F = 0)
  • When the net force acting on an object equals zero, its state of motion will not change and the object is in mechanical equilibrium.