A gymnast's backflip is considered more difficult to do in the layout (straight body) position than in the tucked position. Why?
- The body's rotational inertia is greater in layout position than in tucked position. Because the body remains airborne for roughly the same time interval in either position, the gymnast must have much greater kinetic energy in tucked position to complete the backflip. - The body's rotational inertia is greater in tucked position than in layout position. Because the body remains airborne for roughly the same time interval in either position, the gymnast must have much greater kinetic energy in layout position to complete the backflip. - The body's rotational inertia is greater in layout position than in tucked position. Because the body remains airborne for roughly the same time interval in either position, the gymnast must have much greater kinetic energy in layout position to complete the backflip. - The body's rotational inertia is greater in tucked position than in layout position. Because the body remains airborne for roughly the same time interval in either position, the gymnast must have much greater kinetic energy in tucked position to complete the backflip.
The body's rotational inertia is greater in layout position than in tucked position. Because the body remains airborne for roughly the same time interval in either position, the gymnast must have much greater kinetic energy in layout position to complete the backflip.
Explanation:
A gymnast's backflip is considered more difficult to do in the layout (straight body) position than in the tucked position.
When the body is straight , its moment of rotational inertia is more than the case when he folds his body round. Hence rotational inertia ( moment of inertia x angular velocity ) is also greater. To achieve that inertia , there is need of greater imput of energy in the form of kinetic energy which requires greater effort.
So a gymnast's backflip is considered more difficult to do in the layout (straight body) position than in the tucked position.
When brougth close to the charged sphere A, as charges can move freely in a conductor, a charge equal and opposite to the one on the sphere A, appears on the sphere B surface facing to the sphere A.
As sphere B must remain neutral (due to the principle of conservation of charge) an equal charge, but of opposite sign, goes to the surface also, on the opposite part of the sphere.
If sphere A is removed, a charge movement happens in the sphere B, in such a way, that no net charge remains on the surface.
If in such state, if the sphere B (assumed again uncharged completely, without any local charges on the surface), is touched by an initially uncharged sphere C, due to the conservation of charge principle, no net charge can be built on sphere C.
