ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Newton's Three Laws in Words and Formula. Inertia at Rest, and More.

Updated on July 23, 2012

Yes, you do need to memorize these.

You probably had them memorized when you were in middle school, but by now you've forgotten. Here's a quick refresher.

Isaac Newton's Three Laws
Isaac Newton's Three Laws

1. Law of Inertia

An object at rest remains at rest. An object in motion remains in motion unless acted upon by an outside force.

If F=0, then a=0

(no Force, no acceleration)

When you throw a ball on earth, gravity acts upon it as an outside force, which eventually stops its motion. If you throw a ball in space, it will never stop. It will go on forever until it encounters something that makes it stop, such as the gravitational pull of a star.

2. Law of Acceleration

The acceleration of an object is directly proportional to the force on it and inversely proportional to its mass.

f/m=a (force divided by mass equals acceleration)


f=ma (force equals mass times acceleration)

Basically, a smart car will accelerate much faster than a dump truck. The smart car has smaller mass, so the force applied to it results in higher acceleration. Apply the same amount of force to a dump truck, which has higher mass, and acceleration will be lower.

3. Law of mutual action

For every action, there is an equal and opposite reaction. Forces occur in pairs and the force on one object is equal and opposite of the first force.

A > B + -B > A (Equal and opposite)

Take a look at the skaters below. Their force on each other is equal, but in opposite directions.

Newton's Third Law
Newton's Third Law


    0 of 8192 characters used
    Post Comment

    • stephaniedas profile imageAUTHOR

      Stephanie Das 

      6 years ago from Miami, US

      Hi KenWu- My philosophy is, who really wants to read a long academic hub? When I'm looking for information on things like this, I want it short and sweet. I know what you mean though...E=mc2...I don't even know what it means but I'll always remember it, thanks to the Wizard of Oz. Thanks for commenting!

    • KenWu profile image


      6 years ago from Malaysia

      Short but very academic :)! I had never really interested in Science but those Newton's theory really made sense. BTW, the only science equation that never leaves my mind is Einstein's relativity theory, E=mc2

    • stephaniedas profile imageAUTHOR

      Stephanie Das 

      7 years ago from Miami, US

      I'm glad you think so too! I think its just basic knowledge...if Isaac Newton did all this work for us, we might as well learn his theories.

    • CWanamaker profile image


      7 years ago from Arizona

      Newton was a pretty smart guy. Not only is he credited with these three laws, he created calculus as well. His laws are the basis for the principles that engineer's use to design a lot of the things that we see every day. These concepts are very important for everyone to understand, so I am very excited to have read this hub.

    • stephaniedas profile imageAUTHOR

      Stephanie Das 

      7 years ago from Miami, US

      Thanks! I'm glad I was able to explain them. Sometimes a lot of words get confusing, so I hope the formulas can help people who are more math-minded.

    • ktrapp profile image

      Kristin Trapp 

      7 years ago from Illinois

      I like the examples you give for each of the three laws. It puts a picture in my mind so I can comprehend the formula better. This is a very nice, concise summary of these 3 laws.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)