Acceleration - How do things speed up or slow down?
Welcome to Quatr.us Study Guides!

Acceleration

Kid on bike

November 2016 - Acceleration is a way to measure how fast something is speeding up. Suppose you are riding your bike. You start out going very slowly, hardly pedaling at all. Now you begin to pedal as hard as you can, to speed up - you are accelerating. Now that you are going at a normal speed, you stop pedaling so hard, and just pedal normally. You're still going, but you're not getting any faster, just going along at your normal speed. You're not accelerating anymore.

If you stop pedaling now, friction will work on your bike tires (and you'll have friction from the air, too), and you'll soon start to go slower. That's negative acceleration, or deceleration. You're still going, but you are slowing down.

Cliff diving

One important cause of acceleration is gravity. Suppose you dive off a cliff or a high diving board. You will start off falling slowly, but as gravity pulls on you, you will speed up (accelerate) until you are going very fast.

The acceleration of Earth's gravity will speed you up at about 9.8 meters per second per second (9.8 m/s2, or 9.8 meters per second squared). That means that for every second you fall, you'll be going 9.8 meters/second faster.

Standing on the cliff before you jump, you're going zero meters/second. One second after you jump, you'll be going 9.8 meters/second. Two seconds after you jump, you'll be going 19.6 meters/second. Three seconds after you jump, you'll be going 29.4 meters/second.

You can use acceleration to find out the mass of an object, because force = mass x acceleration. This is how we find out the mass of other stars and planets far away from us.

Learn by doing: ride your bike!
More about acceleration
More about inertia
More about momentum
More about gravity

Bibliography and further reading about acceleration:

Or check out this link to the Encyclopedia Britannica's article on acceleration.

Movement
Space
Physics
Quatr.us home


Please help other teachers and students find us: link to this page from your class page.
Karen Carr is Associate Professor Emerita, Department of History, Portland State University. She holds a doctorate in Classical Art and Archaeology from the University of Michigan. Follow her on Instagram, Pinterest, or Twitter, or buy her book, Vandals to Visigoths.
Karen Carr is Associate Professor Emerita, Department of History, Portland State University. She holds a doctorate in Classical Art and Archaeology from the University of Michigan. Follow her on Instagram or Twitter, or buy her book, Vandals to Visigoths.
Sign up for more free articles and special offers in Quatr.us' weekly newsletter:
We will never share your e-mail address unless you allow us to do so. View our privacy policy. Easy unsubscribe links are provided in every email.
Check out our new ebook: Short and Simple: Ancient Greek Myths! - just out! Twenty-five easy to read, illustrated stories, from Pandora to Medea, Icarus, and the Trojan Horse (you can read these online as samples). Get it this week for just $14.99, five dollars off the regular price of $19.99.
Cite this page
  • Author: K.E. Carr
  • Title:
  • Site Name: Quatr.us Study Guides
  • Publisher: Quatr.us
  • Date Published:
Did you find what you needed? Ask your teacher to link to this page so other people can use it too! Send it in and win a Quatr.us "Great Page!" award!
Sign up for more free articles and special offers in Quatr.us' weekly newsletter:
We will never share your e-mail address unless you allow us to do so. View our privacy policy. Easy unsubscribe links are provided in every email.
Comment on This Article
Quatr.us is loading comments...
(Comments will appear after moderation, if they are kind and helpful. Feel free to ask questions, and we'll try to answer them.)
Cite this page
  • Carr, K.E. . Quatr.us Study Guides, . Web. 18 October, 2017
ADVERTISEMENT