1.
2 answers:
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Answer:
Explanation:
Given data
Power P=4.00×10²W
Radius r=6.5×10⁴m
Voltage V=120V
To find
Length of wire L
Solution
We know that resistance of wire can be obtained from
We also know that R=pL/A solving the length noting that A=πr²
and using p=100×10⁻⁸Ω.m we find that
So
Answer:
3. Her angular speed increases because her angular momentum is the same but her moment of inertia decreases
Explanation:
II ωi the intial angular momentum of the skater. Her angular momentum changes to If ωf after pulling her arms in.
It must be noted that If is less than II, then it is because her arms now go round not far from the rotation axis which brings down the mementos of inertia.
Angular momentum does not change since torque is O.
Note: the mathematical representations are better written on the attached diagram.
