Concept Review: Track Those Spots!
Newton's Laws:
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Newton's 1st Law
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A body at rest tends to remain at rest. A body in motion
tends to remain in motion at a constant speed in a constant
direction unless acted upon by an outside, unbalanced force.
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Newton's 2nd Law
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The acceleration of a body is inversely proportional to its
mass and directly proportional to the force applied.
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Newton's 3rd Law
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For every force there is an equal reaction force in the
opposite direction.
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About the latitude/longitude grid and geometry:
On the latitude/longitude grid, the longitude lines are drawn
at 10o increments. (Remember, if they were drawn at
1o increments, there would be 360 circling all the way
around the sun!)
Latitude lines are also are drawn at 10o
intervals. (Remember, the northern pole of the sun would be at
90o N and the southern pole is at 90o
S.)
Displacement, velocity and acceleration:
Converting distance from degrees to radians
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A full circle contains 360o or
2 pi radians
Degrees = # of degrees
Radians = # of radians
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360o = 2 pi rad
180o = pi rad
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Calculating average velocity
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Average velocity is the rate of change of distance
Don't forget - velocity is a vector quantity with a
direction.
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Average angular velocity:
Angular distance / time
w = q/t
Linear average velocity:
linear distance / time
v = d/t
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Calculating centripetal acceleration
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Centripetal acceleration is the type of acceleration an object
has because it is moving in a circle (not a straight line.)
We assume here that average velocity is constant.
Don't forget - the direction of centripetal acceleration
is always toward the center of the circular path.
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Using translational velocity
ac = v2 / r
Since v = rw, you can substitute rw for v in this equation
to obtain centripetal acceleration
using angular velocity:
ac = w2 r
Note: in both cases r = path radius
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