Roly-poly toy
Encyclopedia
A roly-poly toy, round-bottomed doll, tilting doll, tumbler or wobbly man is a toy
that rights itself when pushed over. The bottom of a roly-poly toy is round, roughly a hemisphere. Many roly-poly toys are hollow, with a weight inside the bottom. It has a center of mass
below the center of the hemisphere, so that any tilting raises the center of mass. When such a toy is pushed over, it wobbles for a few moments while it seeks the upright orientation, which has an equilibrium
at the minimum gravitational potential energy.
The toy can represent a person, an animal, or anything else. Different toy manufacturers and different cultures produce different-looking roly-poly toys: the okiagari-koboshi
and some types of Daruma doll
of Japan
, the nevаlashka or vanka-vstanka of Russia
, and Playskool's Weeble
s. Traditional Chinese examples are hollow clay figures of plump children, but "many Chinese folk artists shape their tumblers in the image of clownish mandarins as they appear on stage; in this way they mock the inefficiency and ineptitude of the bureaucrats". In Japanese a roly-poly toy is called okiagari, meaning to get up (oki) and arise (agari). This characteristic has come to symbolize the ability to have success, overcome adversity, and recover from misfortune.
A toy manufacturer recommends roly-poly toys for small children just developing motor skill
s; a child can bat at it without its rolling away.
Dynamogene Theater stages a performance called "Monsieur Culbuto", allowing the audience to interact with a human dressed as a roly-poly toy.
The Noddy stories by Enid Blyton
have characters Mr. and Mrs Wobblyman, who are based on this sort of roly-poly toy.
Toy
A toy is any object that can be used for play. Toys are associated commonly with children and pets. Playing with toys is often thought to be an enjoyable means of training the young for life in human society. Different materials are used to make toys enjoyable and cuddly to both young and old...
that rights itself when pushed over. The bottom of a roly-poly toy is round, roughly a hemisphere. Many roly-poly toys are hollow, with a weight inside the bottom. It has a center of mass
Center of mass
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body...
below the center of the hemisphere, so that any tilting raises the center of mass. When such a toy is pushed over, it wobbles for a few moments while it seeks the upright orientation, which has an equilibrium
Mechanical equilibrium
A standard definition of static equilibrium is:This is a strict definition, and often the term "static equilibrium" is used in a more relaxed manner interchangeably with "mechanical equilibrium", as defined next....
at the minimum gravitational potential energy.
The toy can represent a person, an animal, or anything else. Different toy manufacturers and different cultures produce different-looking roly-poly toys: the okiagari-koboshi
Okiagari-koboshi
is a Japanese traditional doll. The toy is made from papier-mâché and is designed so that its weight causes it to return to an upright position if it is knocked over...
and some types of Daruma doll
Daruma doll
The , also known as a Dharma doll, is a hollow, round, Japanese traditional doll modeled after Bodhidharma, the founder of the Zen sect of Buddhism. These dolls, though typically red and depicting a bearded man , vary greatly in color and design depending on region and artist...
of Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, the nevаlashka or vanka-vstanka of Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, and Playskool's Weeble
Weeble
Weebles is a trademark for several lines of children's roly-poly toys originating in Hasbro's Playskool division on July 23, 1971. Tipping an egg-shaped Weeble causes a weight located at the bottom-center to be lifted off the ground...
s. Traditional Chinese examples are hollow clay figures of plump children, but "many Chinese folk artists shape their tumblers in the image of clownish mandarins as they appear on stage; in this way they mock the inefficiency and ineptitude of the bureaucrats". In Japanese a roly-poly toy is called okiagari, meaning to get up (oki) and arise (agari). This characteristic has come to symbolize the ability to have success, overcome adversity, and recover from misfortune.
A toy manufacturer recommends roly-poly toys for small children just developing motor skill
Motor skill
A motor skill is a learned sequence of movements that combine to produce a smooth, efficient action in order to master a particular task. The development of motor skill occurs in the motor cortex, the region of the cerebral cortex that controls voluntary muscle groups.- Development of motor skills...
s; a child can bat at it without its rolling away.
Dynamogene Theater stages a performance called "Monsieur Culbuto", allowing the audience to interact with a human dressed as a roly-poly toy.
The Noddy stories by Enid Blyton
Enid Blyton
Enid Blyton was an English children's writer also known as Mary Pollock.Noted for numerous series of books based on recurring characters and designed for different age groups,her books have enjoyed huge success in many parts of the world, and have sold over 600 million copies.One of Blyton's most...
have characters Mr. and Mrs Wobblyman, who are based on this sort of roly-poly toy.