MiniDrillHomework 2

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Mini-Drill/Homework (2)

• Problem 28, page 76 An artillery shell is fired
  with an initial velocity of 300 m/s at 55.0o
  above the horizontal. To clear an avalanche, it
  explodes on a mountainside 42.0 s after firing.
  What are the x and y coordinates of the shell
  where it explodes, relative to its firing point?

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Solution (2)
y
x
(xf, yf)
300 m/s
t 43.0 s
55.0o
yi 0
xi 0
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Step 2.) Find Initial Velocities
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Step 3.) Motion Equations
Horizontal
Vertical
5
Solution Prob. 4 cont
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Mini-Drill/Homework (3)

• A rock is thrown upward from the bottom of a
  canyon at an angle of 47o to the horizontal and
  with an initial speed of 25 m/s. If the rock is
  in flight for 4.0 s, how deep is the canyon?

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Solution (3)
y
x
(xf, yf?)
t 4.00 s
35.0 m/s
47.0o
yi 2.00 m
xi 0
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Step 2.) Find Initial Velocities
This is the only initial velocity we need.
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Step 3.) Motion Equations
Horizontal
Vertical
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Solution Prob. 8 cont