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Sergio [31]
2 years ago
9

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.
Physics
1 answer:
spin [16.1K]2 years ago
6 0

Answer:

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.

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The hoop is attached.

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F = -m·a + m·g·sinθ
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Now, solve for θ:
θ = tan⁻¹(2·μ)
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5 0
2 years ago
If you were to triple the size of the Earth (R = 3R⊕) and double the mass of the Earth (M = 2M⊕), how much would it change the g
EastWind [94]

Answer:

Decreased by a factor of 4.5

Explanation:

"We have Newton formula for attraction force between 2 objects with mass and a distance between them:

F_G = G\frac{M_1M_2}{R^2}

where G =6.67408 × 10^{-11} m^3/kgs^2 is the gravitational constant on Earth. M_1, M_2 are the masses of the object and Earth itself. and R distance between, or the Earth radius.

So when R is tripled and mass is doubled, we have the following ratio of the new gravity over the old ones:

\frac{F_G}{f_g} = \frac{G\frac{M_1M_2}{R^2}}{G\frac{M_1m_2}{r^2}}

\frac{F_G}{f_g} = \frac{\frac{M_2}{R^2}}{\frac{m_2}{r^2}}

\frac{F_G}{f_g} = \frac{M_2}{R^2}\frac{r^2}{m_2}

\frac{F_G}{f_g} = \frac{M_2}{m_2}(\frac{r}{R})^2

Since M_2 = 2m_2 and r = R/3

\frac{F_G}{f_g} = \frac{2}{3^2} = 2/9 = 1/4.5

So gravity would have been decreased by a factor of 4.5  

8 0
2 years ago
A torsional pendulum consists of a disk of mass 450 g and radius 3.5 cm, hanging from a wire. If the disk is given an initial an
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To solve this problem we will use the kinematic equations of angular motion, starting from the definition of angular velocity in terms of frequency, to verify the angular displacement and its respective derivative, let's start:

\omega = 2\pi f

\omega = 2\pi (2.5)

\omega = 5\pi rad/s

The angular displacement is given as the form:

\theta (t) = \theta_0 cos(\omega t)

In the equlibrium we have to t=0, \theta(t) = \theta_0 and in the given position we have to

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Derived the expression we will have the equivalent to angular velocity

\frac{d\theta}{dt} = 2.7rad/s

Replacing,

\theta_0(sin(5\pi t))5\pi = 2.7

Finally

\theta_0 = \frac{2.7}{5\pi}rad = 9.848\°

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6 0
2 years ago
In which of the following examples does the object have both kinetic and potential energy? Select all that apply.
Andru [333]

Objects having both kinetic and potential energy:

water flowing downstream

a child swinging on a swing

a bouncing ball

a plane in flight at 30,000 feet

Explanation:

The kinetic energy of an object is the energy possessed by the object due to its motion. It is given by

KE=\frac{1}{2}mv^2

where

m is the mass of the object

v is its speed

Therefore, an object has kinetic energy when its speed is non-zero (so, whenever it is moving).

The potential energy of an object is the energy possessed by the object due to its position in the gravitational field. It is given by

PE=mgh

where

m is the mass

g is the acceleration of gravity

h is the heigth of the object relative to the ground

Therefore, an object has potential energy whenever it is located at a certain height above the ground.

So in this problem, the objects that have both kinetic and potential energy are:

a rock at the edge of a cliff  --> NO, because the rock is at rest (so KE = 0)

water flowing downstream  --> YES, because the water is moving AND it is at a certain height above the ground

a child swinging on a swing  --> YES, because the child is moving AND it is at a certain height above the ground

a bouncing ball  --> YES, because the ball is moving AND it is at a certain height above the ground

water behind a dam  --> NO, because the water is at rest (so KE=0)

a car moving on a level road  --> NO, because the car is at ground level (so PE=0)

a plane in flight at 30,000 feet   --> YES, because the plane is moving AND it is at a certain height above the ground

a compressed spring --> NO, because the spring is at rest (so KE=0)

Learn more about kinetic and potential energy:

brainly.com/question/6536722

brainly.com/question/1198647

brainly.com/question/10770261

#LearnwithBrainly

8 0
2 years ago
Anna drives north at a speed of 50 km/h for the first hour. Then, she drives north for a second hour but slows down to 30 km/h.
8090 [49]

Answer:

The correct answer is A The distance is greater in the first hour because her speed is faster.

Explanation:

During the first hour, Anna is driving at a speed of 50 km/h. During the second hour, she is only driving at a speed of 30 km/h. The faster she goes, the farther she will go.

Hope this helps,

♥<em>A.W.E.</em><u><em>S.W.A.N.</em></u>♥

8 0
2 years ago
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