Design Con 2015
Breaking News
Blog

The force that pulls dogs toward the groins of strangers

NO RATINGS
View Comments: Newest First | Oldest First | Threaded View
Page 1 / 4   >   >>
syzygy
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
syzygy   7/8/2011 9:30:43 PM
NO RATINGS
Put a ping pong ball on the edge of a turntable that plays LPs (if you have one). Set it up so that as the turntable turns the ball stays in the same place. Then give the ball a little poke to push it into the center. Watch it go in a circle. Figure out why and I think you'll have your answer.

Tazman
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
Tazman   6/16/2011 8:50:38 PM
NO RATINGS
F=mv**2/r =100kg * ((447m/s)**2) / 6149045m =3.25 Newtons =.73 lbs less "weight" at equator for 100kg object

Itinerant Engineer
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
Itinerant Engineer   6/3/2011 4:38:52 PM
NO RATINGS
@corndodger: "There is no "horizontal" force..." Yes, the word "horizontal" was misused -- in each case, the intended word was "tangential". @corndodger: "Cut the string and the ball flies away from you in the direction it was pointing when the string was cut." If you're going to be pedantic about it, the ball will fly away in a direction perpendicular to the "direction it was pointing when the string was cut." The ball continues in the direction it was moving, not pointing, at the instant the centripetal force was removed. @corndodger: "Sit in the center of a spinning merry-go-round, ball in hand. Let go of the ball. The ball leaves, rolling straight out from the center where you're sitting..." Actually, barring friction with the surface of the merry-go-round, in your rotating reference frame, the ball will appear to slide outwards in a *trailing spiral* since it's velocity remains constant but it's angular velocity decreases as the radius increases. Add friction, and the ball's outward spiral gets deformed due to the rotational inertia of the ball as it comes up to speed with the surface of the merry-go-round. As for your word "centrifical", the word for the stipulated force allowing you to treat a rotating frame as an inertial frame is "centrifugal". Perhaps you should consult something a little more advanced than _Sandbox Science_ before you go correcting others. Lance ==)-------------

corndodger
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
corndodger   6/3/2011 3:34:43 PM
NO RATINGS
I was taken aback by you discussion of a "horizontal" component to the ball being swung around your head and feet. The ball must have hit your head a couple of times too many. There is no "horizontal" force, only the centrifical force that pulls the ball away from you, stretching the string. Cut the string and the ball flies away from you in the direction it was pointing when the string was cut. It does not follow the circular path it was in prior to release. This information can be found in any pre-school physics book. (This is too basic for Kindergarten students.) Want further confirmation? Sit in the center of a spinning merry-go-round, ball in hand. Let go of the ball. The ball leaves, rolling straight out from the center where you're sitting, and continues rolling straight away once it is on the ground. corndodger

Itinerant Engineer
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
Itinerant Engineer   6/3/2011 11:21:11 AM
NO RATINGS
Air pressure, more specifically, air density and thus buoyancy, would have an effect, but it would be immeasurably small. The rate at which you lose mass due to sweating would likely have a greater effect. I once posed a puzzle along the lines of "Which weighs more at STP: a kilogram of gold or a kilogram of aluminum"; I was looking for the buoyancy effect, but found that the oxidation of the outer surface of the aluminum increased its weight by more than the decrease due to buoyancy. Lance ==)-------------

Max The Magnificent
User Rank
Blogger
re: The force that pulls dogs toward the groins of strangers
Max The Magnificent   6/2/2011 6:47:03 PM
NO RATINGS
@ck_02: Well, it's just so crazy it may work. Did you read my Discworld blog (http://bit.ly/mRLJN5). Your comment reminded me of the scene in Guards! Guards! Where our three heroes are on the roof with one about to shoot an arrow at a dragon to hit its "vulnerable spot" and one says something like "it's a million to one chance but it just might work" and another says "it has to work because a million to one chance always works in stories." But then one remembers that the guy who is going to fire the arrow won a competition in archery and is also going to use his lucky arrow .. and after some debate they decide that it's more of a thousand to one shot, and whoever heard on that working in a story? So they start to handicap the archer by having him stand on one leg and close one eye and ... until they recon they've managed to get the odds back up to a million to one ... I love this stuff :-)

ck_02
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
ck_02   6/2/2011 6:40:24 PM
NO RATINGS
However, if a ventilation system were in place that kept constant pressure and air volume into account while providing said subject with a measured amount of breathable air that would have to be taken at the time of each weigh-in. Well, it's just so crazy it may work.

Duane Benson
User Rank
Blogger
re: The force that pulls dogs toward the groins of strangers
Duane Benson   6/2/2011 6:32:46 PM
NO RATINGS
Relative to any difference that might occur and be measurable in the effective weight due to your position on the globe, the donut factor, as alluded to by ck_02, would be an order or two of magnitude greater in impact. Certainly, sealing yourself into a plastic bag would prevent the donut factor from influencing your measurements. However, the plastic bag would in a short span of time, lead to your inability to continue with your measurements. Unfortunately, it would not make you a closed system as plastic does, at very small rates, allow the permeation of moisture and various gasses. In conclusion, I would not recommend sealing yourself into a plastic bag. While it would prevent some influences, it would ultimately fail in creating a completely closed system and therefore would call your data into question.

ck_02
User Rank
Rookie
re: The force that pulls dogs toward the groins of strangers
ck_02   6/2/2011 6:30:41 PM
NO RATINGS
That option screams terrible B-rated horror flick all over it. sorry. ;)

Max The Magnificent
User Rank
Blogger
re: The force that pulls dogs toward the groins of strangers
Max The Magnificent   6/2/2011 5:07:00 PM
NO RATINGS
How about if I seal myself in a plastic bag so as to become a closed system? :-)

Page 1 / 4   >   >>
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week