A ballerina spins initially at 1.5 rev/s when her arms are extended. She then draws in her arms to her body and her moment of inertia becomes 0.88 kg ? m2, and her angular speed increases to 4.0 rev/s. What was her initial moment of inertia?
What will be an ideal response?
2.3 kg ? m2
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A very thin uniform rod, 2.40 m long and of weight 135 N, has a frictionless hinge at its lower end. It starts out vertically from rest and falls, pivoting about the hinge
Just as it has rotated through an angle of 55.0°, what is the downward acceleration of the end farthest from the hinge? A) 5.02 m/s2 B) 8.03 m/s2 C) 9.80 m/s2 D) 12.0 m/s2 E) 19.6 m/s2
An ideal parallel-plate capacitor consists of a set of two parallel plates of area A separated by a very small distance d. When the capacitor plates carry charges +Q and -Q, the capacitor stores energy U0
If the separation between the plates is doubled, how much electrical energy is stored in the capacitor? A) 4U0 B) 2U0 C) U0 D) U0/2 E) U0/4
What is the equivalent capacitance of the combination shown?
a.
29 µF
b.
10 µF
c.
40 µF
d.
25 µF
The change in electrical potential energy per unit of charge that is moved from one place to another is known as ________
What will be an ideal response?