physics: force. physics physics is the science of understanding forces a force is a push or pull. it...
TRANSCRIPT
![Page 1: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/1.jpg)
Physics: Force
![Page 2: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/2.jpg)
Physics• Physics is the science of understanding
forces• A force is a push or pull. It has both
direction and magnitude (strong/weak)• General forces include gravity and
friction• Elastic forces include compression,
tension, and torque
![Page 3: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/3.jpg)
• Gravity is a force that pulls towards the center of the Earth
Gravity & Weight
![Page 4: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/4.jpg)
• Weight is a force that is a measure of gravity’s pull on an object
Gravity & Weight
Turkey
Scale
![Page 5: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/5.jpg)
To calculate the weight force of gravity’s pull on an object, multiply mass by gravity:
1. Convert mass in grams to kilograms (move the decimal to the left three places)
2. Multiply by gravity which on Earth is 9.8
Calculating Weight Force
![Page 6: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/6.jpg)
• The unit for all forces is the Newton (N)• Named after Isaac Newton, the famous
physicist
Unit
![Page 7: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/7.jpg)
If mass = 215 gforce = .215 x 9.8
= 2.107 = 2.1 N
Examples:
If mass = 1.2 gforce = .0012 x 9.8 = 0.01176 = 0.01 N
![Page 8: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/8.jpg)
• Gravity increases with mass
Understanding Gravity
•Gravity decreases with distance
Large MassMore Gravity
Small MassLess Gravity
![Page 9: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/9.jpg)
•Think of gravity as massive objects creating warps in the fabric of space
Understanding Gravity
![Page 10: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/10.jpg)
Understanding Gravity – Newton vs Einstein
![Page 11: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/11.jpg)
• Two forces are always opposing motion: –Gravity–Friction
Gravity & Friction Oppose Motion
![Page 12: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/12.jpg)
• Gravity is a force that slows upward and trajectory (on a path) motion by pulling objects towards the Earth
Gravity Opposes Motion
Gravity slows upward motion
Gravity slows forward motion
![Page 13: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/13.jpg)
• Gravity pulls all objects to the Earth at the same rate no matter if they are dropped or shot from a gun
Gravity Opposes Motion
![Page 14: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/14.jpg)
• Friction is a force that opposes motion between touching surfaces
Motion Force
Friction Force
Friction Opposes Motion
It is hard to walk without friction
![Page 15: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/15.jpg)
• The space shuttle and meteors (shooting stars) have air friction between their surface and our atmosphere
Friction Opposes Motion
![Page 16: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/16.jpg)
• Friction creates heat and wears out objects
Hip Replacement
Friction Opposes Motion
![Page 17: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/17.jpg)
• Lubrication, such as oil and grease, help reduce friction
Friction Opposes Motion
![Page 18: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/18.jpg)
• There are two basic types of friction: static and kinetic.
• Static friction is the stronger force of the two.
Friction Opposes Motion
![Page 19: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/19.jpg)
• Static friction occurs before movement takes place - it resists movement.
Motion ForceFriction
Force
Friction Opposes Motion
![Page 20: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/20.jpg)
• Kinetic friction occurs during movement - it tries to slow or stop movement.
Motion Force
Friction Force
Friction Opposes Motion
![Page 21: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/21.jpg)
Example QuestionWhat two forces oppose the motion of this bike?
Motion ForceFriction
Force
GravityForce
![Page 22: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/22.jpg)
Elastic ForcesCompression
• Forces come together from opposite directions (crushing a can)
Don’t try this at home!
![Page 23: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/23.jpg)
• Forces applied in opposite directions (tug of war)
Elastic Forces (continued) Tension
![Page 24: Physics: Force. Physics Physics is the science of understanding forces A force is a push or pull. It has both direction and magnitude (strong/weak) General](https://reader036.vdocuments.mx/reader036/viewer/2022062421/56649dfe5503460f94ae660b/html5/thumbnails/24.jpg)
Elastic Forces (continued)T o rque
• A twisting force (the ‘O’ in torque)