Centripetal Force and
Projectiles
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Gravity Review
Weight is a force due to gravity
Specifically, the weight of something
is the force that is exerts against
the supporting floor or weighing
scale
Weight
Support Force
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Centripetal Force
Centripetal force is any force that causes an
object to follow a circular path.
Centripetal means towards the center
Demonstration:
http://www.youtube.com/watch?v=Sav9vQ6
63u4
http://www.youtube.com/watch?v=Vpyx7Gu
0hos
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Centripetal Force
How would the tension in the string be
affected?
f = m v2
r
Remember 1/r does the opposite to the force!
If r gets bigger, the force will get smaller
If r gets smaller, the force will get bigger
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Centripetal Force and
Simulated Gravity
http://www.youtube.com/watch?v=N
w_k9jKyQeU
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Projectile Motion
What is a Projectile?
A projectile is any object that is
projected (or thrown) by some means
and continues in motion by its own
inertia
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Projectiles
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Projectile Motion
Thrown
Falling due
to Gravity
Actual
Path
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Projectile Motion
Thrown
Gravity
Thrown
with gravity
Thrown with Gravity = Gravity + Thrown (kind of)
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Projectile Motion
Thrown –
Constant
Gravity – has an
acceleration
(10 m/s2)
velocity
Thrown
with gravity
Changing Velocity
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Projectile Motion
v = 5 m/s at
all times
At t = 0 s ,
v = __ m/s
At t = 1 s ,
v = ___ m/s
At t = 2 s ,
v = ____m/s
At t = 3 s ,
v = ____m/s
To calculate actual
velocity, use
Pythagorean
Theorem
At t = 4 s ,
v = ___m/s
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Projectile Motion
Same applies to upward moving objects!
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Projectile Motion
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