## How does the size of a ball affect the speed?

Ask questions about projects relating to: aerodynamics or hydrodynamics, astronomy, chemistry, electricity, electronics, physics, or engineering

Moderators: MelissaB, kgudger, Ray Trent, Moderators

### How does the size of a ball affect the speed?

I'm looking for research on how the size of a ball will affect the speed. Can anybody help?
ttaylor

Posts: 2
Joined: Tue May 01, 2012 10:31 am
Occupation: Mother
Project Question: How does the size of a ball affect the speed?
Project Due Date: May 21, 2012
Project Status: I am conducting my research

### Re: How does the size of a ball affect the speed?

Dear ttaylor,

For the research you are interested in, I would highly suggest looking more into Newton's Laws of Motion. Perhaps, you could then design an experiment to test how the size of a ball affects the speed. For example, you could drop balls of different sizes from a known height and measure their speed as they fall and the time it takes them to fall. Please let me know if I can help you design an experiment with your specific questions?

Jay
jmehta14
Expert

Posts: 55
Joined: Tue Aug 30, 2011 11:16 am
Project Question: Do probiotics with antibiotics have a greater affect on different types of bacteria?
Project Due Date: March 1st
Project Status: I am finished with my experiment and analyzing the data

### Re: How does the size of a ball affect the speed?

I would love the help to design an experiment. I will look up Newton's law in the meantime. I appreciate your help.
ttaylor

Posts: 2
Joined: Tue May 01, 2012 10:31 am
Occupation: Mother
Project Question: How does the size of a ball affect the speed?
Project Due Date: May 21, 2012
Project Status: I am conducting my research

### Re: How does the size of a ball affect the speed?

ttaylor,

I hope your research is going well. Did you ever decide on an experiment proceedure? A slightly different approach to the one suggested by Jay is the one that proves that 2 objects of the same size but different mass still fall at the same rate.

http://www.sciencebuddies.org/science-f ... p015.shtml

For the experiment suggested, since we already know that the objects, regardless of mass, will fall at the same rate, what you are testing is the effect of drag as the object moves through the air around it.

Assuming you are still conducting the experiment, I would suggest getting 2 (or more) balls of significant size difference (say a large beach ball and a tennis ball) and drop them from a known height and measure the time it takes to hit the ground. Since we know the accelleration due to gravity (9.8 m/s^2), you can calculate the average velocity. Any change would be due to drag (in large part) as a function of the cross sectional area of each ball. The larger the cross section area of the object, the larger the coefficient of drag, etc... This experiment can be extended to objects of different shapes to test the effects of aerodynamic properties of say a cone shape vs a blunt faced object, like a cube.

Hope this helps.

theborg
----------
Science Buddies science fair guide:
http://www.sciencebuddies.org/science-fair-projects/project_guide_index.shtml

Science Buddies project ideas:
http://www.sciencebuddies.org/science-fair-projects/project_ideas.shtml
theborg
Moderator

Posts: 261
Joined: Mon Oct 03, 2011 12:26 pm
Occupation: US Air Force Space & Missile Operations
Project Question: "To explain all nature is too difficult a task for any one man. 'Tis much better to do a little with certainty and leave the rest for others that come after you, than to explain all things by conjecture without making sure of anything." - Sir Isaac Newton
Project Due Date: N/A
Project Status: Not applicable