NEWTONS 2nd LAW

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NEWTONS 2nd LAW
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Newtons 2nd Law and Centripetal Force
-Newtons 1st law stated An object at rest
tends to ____________________________ an object
in motion tends to __________________________
as long as the forces are balanced.
stay at rest
stay in motion
change
-If the forces are unbalanced, the motion of the
object will ___________.
-Newtons 2nd law states (part 1) When an
unbalanced force acts on an object, the object
will ___________________ in the direction that
the unbalanced force points.
accelerate
-The greater the force on an object, the greater
the________________. -The larger the ________ of
an object, the larger the force necessary for
acceleration.
acceleration
mass
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-Newtons 2nd law states (part 2) The strength
of the force equals the _________ of the
object multiplied by the _______________ of the
object. Force __________ x
___________________ F x
mass
acceleration
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remember 1N 1kg m/s
F
acceleration
mass
(N)
(kg)
m
(m/s )
2
x
a
m
a
Ex. A baseball player hits a 0.1 kilogram
baseball to accelerate it at a rate of
4000 meters per second squared. What is the
force of the players hit? Ex. A
stalled car has a mass of 1000 kilograms. It is
pushed forward with a force of 2000
newtons. At what rate does the car accelerate?
m 0.1 kg
a 4000 m/s2 0.1 kg x 4000 m/s2
F m x a
400 kg x m/s2
or 400 N
a F m
F 2000N or 2000 kg x m/s2
2000 kg x m/s2 m
1000 kg 1000 kg

2 m/s2
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Deceleration -To decrease the velocity of an
object, the force must be applied in the
direction _______________ of the motion. Often
this force comes from ___________.
opposite
friction
Centripetal force -This is the force that
___________ or ___________ on an object into
a ________________ path. If you recall
-If you change the direction of an object, you
change its ________ -If you change
the velocity of an object, you change its
_________
pushes
pulls
circular
velocity
acceleration
-Therefore, an object traveling at a constant
speed is accelerating when it is not traveling in
a straight line. According to Newtons 2nd law,
since the object is accelerating an unbalanced
force must be changing the direction of motion.
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A?
B?
C
C?
D?
It is always trying to travel in a straight
line perpendicular to the string (tangent to the
circle), but as long as you are holding the
string (applying a force) it must change
directions.
Which direction will the ball travel after it is
released?
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Falling Objects -As objects fall towards the
ground they pick up speed due to the force of
______________. -All objects ______________
toward the ground at the same rate. -On earth
the acceleration of falling objects is
________m/s2. -Falling objects will continue to
accelerate until they reach the ground unless
they are acted upon by an opposing force to
balance out gravity. A force that commonly
opposed the acceleration of falling is
__________________.
gravity
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accelerate
9.8
2
19.6
9.8
3
29.4 m/s
air friction
-When a falling object stops accelerating, it has
reached its _______________
__________________. -Ever object falling through
air, if it is falling long enough, reaches a
_______________ __________________.
terminal
velocity
terminal
velocity
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-Factors that affect terminal velocities
- shape of the object (aerodynamics)
-air thickness
-How does horizontal motion affect rate of fall?
(this arrow will be dropped vetically from the
same height at the moment he shoots)
-they would hit the ground at the same time!