Answer:
C. her moment of inertia increases and her angular speed decreases
D. her moment of inertia increases and her angular speed decreases
Explanation:
The moment of inertia of a body is the sum of the products of an increment of mass and the square of its distance from the center of rotation. When a spinning person extends her arms, part of her mass increases its distance from the center of rotation, so increases the moment of inertia.
The kinetic energy of a spinning body is jointly proportional to the moment of inertia and the square of the angular speed. Hence an increase in moment of inertia will result in a decrease in angular speed unless there is a change in the rotational kinetic energy.
This effect is used by figure skaters to increase their spin rate by drawing their arms and legs closer to the axis of rotation. Similarly, they can slow the spin by extending arms and legs.
When the person extends her arms, her moment of inertia increases and her angular speed decreases.
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<em>Note to those looking for a letter answer</em>
Both choices C and D have identical (correct) wording the way the problem is presented here. You will need to check carefully the wording in any problem you may think is similar.
Work done to lift the rock is 6174 Joule.
To find the answer, we need to know about the work done.
<h3>What's the work done?</h3>
Mathematically, work done = force × distance
<h3>What's the gravitational force acts on the stone here?</h3>
The gravitational force on the stone = mg
= 210× 9.8= 2058N
<h3>What's the work done to lift the stone?</h3>
Work done= 2058× 3
= 6174 Joule
Thus, we can conclude that the work done to lift the stone is 6174 Joule.
Learn more about the work done here:
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laser in the garage . . . D
wavelength of a sound . . . C
how sound travels . . . B
electromagnetic spectrum . . . D
The four ways to
incorporate evidence into the research paper are:
<span>1.
</span>If the research you
are investigating has been with other research paper before.
<span>2.
</span>There is an
experimental proof that the evidence is true.
<span>3.
</span>The research
published belongs to a reliable source.
<span>4.
</span><span>There are citations
of the evidence that you are investigating</span>
Answer:
The velocity of an object refers to the rate at which the object's position changes. For any given motion, it is possible that an object could move very fast yet have an abnormally small
Formula:
velocity = distance travelled in a straight line/ time taken
