First, a quick rundown of the anatomy of a yo-yo: two disks of equal size are placed together and connected with a little part in the middle called an axle.
A string is affixed to the yo-yo, either by tying a loop around the axle or by attaching the end of the string directly to a point in the axle.
A yo-yo is able to “sleep,” or stay spinning at the bottom of the string, because as the string loops around the axle, gravity keeps it down instead of winding the yo-yo back up.
The axle has to be smooth enough that it can spin freely in the loop of the string, yet has to have just enough friction that when you jerk the string, the axle will grip it and wind back up.
When you want the yo-yo to come back up, a simple jerk will begin the process of the string wrapping around the axle. Of course, none of this works at all the yo-yo will not “sleep” if the string is affixed to only one place on the axle.
Related Posts
-
How Do Birds Sleep Without Falling Out of Trees and Do Birds Sleep Laying Down or Standing Up On Perches?
Birds have a nifty tendon arrangement in their legs which help them sleep when they are perched. The flexor tendon from the muscle in the thigh reaches down over the knee, continues down…
-
How did the G string get its name and Where does the term “G string” come from?
Let me say at the outset that the reason one or the other of the term "G string" was given to the type of breechclout worn by some Native Americans has never been…
-
How Long Can a Sea Turtle Stay Underwater and Hold its Breath Without Coming to the Surface for Air?
If a Sea Turtle has been swimming, it can stay underwater for a few minutes. If resting, it can stay underwater as long as two hours. Sea turtles are almost always under water,…
-
How Much Sleep Do Giraffes Need and How do They Have the Shortest Sleep Requirements of Any Mammal?
The giraffe has one of the shortest sleep requirements of any mammal. Giraffes sleep between ten minutes and two hours in a 24-hour period, averaging about 2 hours per day. Since an adult…
-
Why Do Babies Sleep So Much and How Fast Do Babies Grow When They Sleep?
One reason babies sleep so much is that human growth factor, made by the pituitary gland, is secreted during sleep in higher concentrations than when the baby is awake. How the body and…
-
Why Is An Hour of Sleep Before Midnight Worth Two Hours of Sleep After Midnight?
It's not true that an hour of sleep before midnight is worth two hours of sleep after midnight. Sleep needs are much more complicated than that. The hour of rising is probably much…
