Chapter 6: Dynamics II: Motion in a Plane

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Chapter 6 Dynamics II Motion in a Plane

• 6.1 Kinematics in two Dimensions
• 6.2 Dynamics in Two Dimensions
• 6.3 Projectile Motion
• 6.4 Relative Motion

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Position and Velocity
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Instantaneous velocity
The Instantaneous velocity vector is tangent to
the trajectory. The direction of the velocity is
to the curve.
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Dont confuse these two graphs
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Acceleration
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The instantaneous acceleration can bedecomposed
into parallel and perpendicular components
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Projectile Motionobject moves in two dimensions
under the gravitational force.
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Plot of projectile motion in t-xy
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Launch angle
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Ex. A ball thrown horizontally at velocity Vi ,
travels a horizontal distance of R m before
hitting the ground. From what height was the ball
thrown?(1) Since ball is thrown horizontally,
Vi VxThere is no acceleration at x
direction.ie. R Vxt, t R/Vx(2) Viy0, h
-1/2gt2
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Problem 42
Solve a quadratic equation to get t
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The maximum height and distance of fly ball

• For projectile motion, always remember

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Relative Motion

• Relative position
• Relative velocity