Weight
Download
1 / 8

Weight - PowerPoint PPT Presentation


  • 304 Views
  • Updated On :

Weight Acceleration of Gravity Objects that fall to the Earth all experience an acceleration. The acceleration due to gravity is g = 9.8 m/s 2 . This acceleration must be due to a force. The acceleration of a falling mass m is - g .

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 'Weight' - libitha


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

Acceleration of gravity l.jpg
Acceleration of Gravity

  • Objects that fall to the Earth all experience an acceleration.

  • The acceleration due to gravity is g = 9.8 m/s2.

  • This acceleration must be due to a force.


Force of gravity l.jpg

The acceleration of a falling mass m is -g.

The force on the mass is found from F = ma (action).

This gravitational force is F = -mg.

Force of Gravity

Kinematic view

Dynamic view


Gravity at rest l.jpg
Gravity at Rest

  • The force of gravity acts on all objects all the time.

  • If an object is at rest, the law of inertia says that the net force is zero.

  • There must be a force opposite to gravity that cancels it out.

F = -Fgrav =mg

Fgrav = -mg


Normal force l.jpg
Normal Force

  • The force that opposes gravity for objects on the ground is called the normal force.

  • It is perpendicular (normal) to the plane of the ground.

  • The force is a result of the law of reaction.

FN = mg

Fsb = -Fbs =mg


Normal force and weight l.jpg
Normal Force and Weight

  • The normal force pushing up against gravity can be measured.

  • We measure weight with a scale that measures normal force.

  • Weight is a force, not a mass.

  • Pounds measure weight, so force (not mass) can be measured in pounds.


Accelerated weight l.jpg
Accelerated Weight

  • An elevator is accelerating downward at 2.0 m/s2.

  • The person has a mass of 70 kg.

  • What weight is on the scale?

  • Add all the forces, but the net force is –ma = FN – mg.

  • Solve for FN = m (g – a)

  • The scale shows 56 kg.


Weightlessness l.jpg
Weightlessness

  • If the elevator accelerated downward at g, the normal force would become 0.

  • The person would feel weightless.

  • An object in free fall is weightless, but not massless.

Microgravity research at NASA

next