Outline

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Outline
Free Fall and Inclined Plane

• Kinematic Equations of Constant Acceleration
• Kinematics on an Inclined Plane
• Examples
• Quiz

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The equations of motion
The equations of motion
Caution These are correct only if a is
constant!
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Example 1 You drop a rock from rest from the
edge of a cliff. If the rock takes 4.0s to hit
the ground below, how tall if the cliff ?
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Example 2 You throw a rock with initial
velocity of 10m/s up from the edge of a cliff.
If the rock takes 5.0s to hit the ground
below,a) how tall if the cliff ? b) how
fast is the rock moving when it hits the ground?
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Example 3 You drop a rock from rest from the
edge of a cliff. If the cliff is 45m tall,a)
how long will the rock take to hit the ground
under the cliff ?b) how fast will the
rock be moving when it hits the ground ?
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Block on an incline
Right angle
Symbols for parallel and perpendicular
Accelerationsa g sin ?
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Example 4 A block on an incline of 30o is
released from rest. a) How far will be block
move in 2 seconds?b) What will the blocks
speed be at 2 seconds ?c) What is the average
velocity of the block during the 2 seconds?
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Ex. Kinematics on an Inclined Plane
Example 5
On a level road, the magnitude of a particular
cars maximum acceleration is 6 m/s2. That car
drives up a hill that makes an angle of 30? to
the horizontal. If it starts at the bottom of the
hill at 10 m/s, how far will it travel in 10
seconds if it is accelerating as much as it can?

1. 0.15 km
2. 0.5 km
3. 1.5 km
4. 2.5 km

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Do for next class

• Read Sections 3.3, 3.4
• Suggested problems 3.9, 3.13