Lecture 1: Introduction Motion in 1D

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Lecture 1IntroductionMotion in 1-D

• Phys 2101
• Gabriela González

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The basics about the course
Instructor Gabriela González (www.phys.lsu.edu/fa
culty/gonzalez/) Office hours MF 2-3pm, 271-C
Nicholson Hall Course website
www.phys.lsu.edu/classes/spring2008/phys2101/ Text
bookFundamentals of Physics, Halliday, Resnick,
and Walker, 8th ed., 2001 (LSU custom edition is
cheaper, and has WebAssign code) Homework
www.webassign.net/login.html Grades 1
initial exam (next week!)x 50 3
hour exams x 100
final exam x 200
homework x 100 600
A  85-100   B  75-85      C  60-75     
D 50-60      F  lt50
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Motion in one dimension

• Position is a function of time x(t)
• Velocity is also a function of time, defined as

• Acceleration is defined as

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Constant 1-D acceleration
the only formulas you need!
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Motion in one dimension

• The diagram shows the position of a cross-country
  skier at various times. At each of the indicated
  times, the skier turns around and reverses the
  direction of travel the skier moves from A to B
  to C to D.
• What is the average speed and the average
  velocity of the skier between t0 and t1, 2 and
  3min?
• Plot the skiers position, velocity and
  acceleration as a function of time.

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Constant acceleration

• A model rocket fired vertically from the ground
  ascends with a constant vertical acceleration of
  5 m/s2 for 6 s. Its fuel is then exhausted, so
  it continues upward as a free-fall particle and
  then falls back. Assume g10 m/s2.
• Plot the acceleration, velocity and position as a
  function of time.
• What is the maximum altitude reached?
• What is the total time elapsed from take off
  until the rocket strikes the ground?