HW 8 Solutions

2 cos 30 2 3 h c h h h a 3 apply the definition

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Unformatted text preview: the distance from the distance of the three the geometry, the central hydrogen to the atoms on the vertex. if the distance beH nuclei from the rotation axis is tween the hydrogens is a, then the radius ais 3 , where a is the length of a side / a2 a a1 r= of the tetrahedron. ◦ = √ = √ . 2 cos 30 2 3 H C H H H a 3 Apply the definition of the moment So, we ﬁnd that of inertia for a system of particles to I= obtain: I = ∑ mi ri 2 = mH r12 + mH r22 + mH r32 Substitute numerical values and evaluate I: I = 1.67 × 10 − 27 kg 0.18 × 10 −9 m i 2 2 3mH ⎛a⎞ ⎟ = mH a 2 = mH= 3mH ⎜ a ⎝ 3 ⎠2 = (1.67 × 10−27 ) (0.18 × 10−9 ) = 5.41 × 10−47 kg m2 . a √ 3 2 ( )( = 5.4 × 10 − 47 kg ⋅ m 2 2 ) 2 ⎝ ⎠ us sign is a consequence of the fact that the frictional torque otion of the wheel. 3. A pendulum consisting of a string of length L attached to a bob of mass m swings in a vertical plane. When the string is at an angle θ to the vertical, endulum consisting tangentialstring of length L attached to a bob of (a) c...
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This document was uploaded on 03/14/2014 for the course PHYS 18 at UC Merced.

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