Physics 1A, Section 6

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Physics 1A, Section 6

• October 16, 2008

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Section Business

• Quiz 1 was due 3 hours ago!
• Homework and quiz solutions will be posted
  on-line on the course web page.

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T.M.U.Problem 6.4
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T.M.U.Problem 6.4

• Answer Equal force acceleration greater for bug

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T.M.U.Problem 6.1
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T.M.U.Problem 6.1

• Answer Accelerate equally, and compare the
  force required.

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T.M.U.Problem 6.5
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T.M.U.Problem 6.5

• Answer (a) and (b) are reaction pairs (c) and
  (d) are not

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T.M.U.Problem 6.6
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T.M.U.Problem 6.6
accelerates to the left
doesnt accelerate
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T.M.U.Problem 6.3
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T.M.U.Problem 6.3

• Answer Tension greatest between engine and
  front boxcar. Tension is 3ma, 2ma, ma from front
  to back.

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Final Problem 9
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Helpful hints

• Free body diagrams a good start.
• Be consistent with signs.
• massless strings tension is constant along the
  free length
• frictionless/massless pulleys rope tension is
  constant over the pulley

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Pulley
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Pulley

• Answer in more general case

tension T
force T
force T
tension T
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Final Problem 9

• Answer
• m2/m1 1
• DD1 DD2/2
• a2 2g/9
• v2 2/3 sqrt(gD), v1 1/3
  sqrt(gD)
• decrease

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Monday, October 20

• a gravity/circular orbit problem of some sort
• Quiz Problem 37
• Optional, but helpful, to look at these in
  advance.

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T.M.U.Problem 6.2