DYNAMICS handout
III. Dynamics - study of the relationship between ______________ and ________
A) Newton's Three Laws of Motion
1st Law Law of ___________________
"An object at rest tends to stay at ________________.
An object in motion tends to stay in _______________ in straight line unless
acted on by an unbalanced ___________________."
Another words … If a moving object has no unbalanced force on it, it would
__________________________________________________________________________
The larger the mass, the _______________________ inertia
2nd Law Relationship between _____________________________
Applying an unbalanced force on an object causes that
object to ___________________________according to the equation
(m) a = __ __ (N)
(s 2) (Kg)
1. Acceleration is ___________________ related to the force exerted on that
object.
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a |
F |
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X 3 |
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x 2 |
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¸ 3 |
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¸ 2 |
a
= __F __
m
2. The acceleration a given force will produce on an object is
_____________ proportional to the mass of the object.
F = 10nt F = 10nt
m = 2kg m = 4kg
a = 5 m/s2 a = ______m/s2
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a |
M |
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¸2 |
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x2 |
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x3 |
3. Inertial mass (solve for m) You can calculate the mass of an object by
__________________________________
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Inertial mass m =
|
4. Standard equation F = ma
(N) (Kg) (m/s 2)
Newton - defined - force needed to give a ____________ of mass an
acceleration of ___________
Derived unit - A unit that comes from the __________________
__________________________________________________________
N = Kg m/s 2
Fundamental unit - (opposite) _________________
Force Questions
Ex1) What is the force necessary to give a 3kg mass, initially at rest, an acceleration of 5 m/s 2 ?
F = ma
Ex2) A force of 30 nt accelerates an object by 15 m/s2. Find the objects mass.
F = ma
Ex 3) An unbalanced force of 100 nt acts on a 50kg mass for 5 seconds.
Find the acceleration of the mass
Ex 4) A 10 kg cart moving with a velocity of 2m/s is brought to a stop in 2 sec. Find magnitude of the average force used to stop cart.
3rd Law of Motion
For every action there is _____________________________________________
A lamp applies a force of 10 N to a table. What force does the table apply on the lamp? Which direction is this force applied?
B) Free Body Diagrams - diagrams that show the forces acting on an object
Ex1)
Weight = mg
About the Normal Force
(1) __________________ force supporting an object
(2) Always drawn _____________________to surface where 2 objects meet
(3) When an object is placed on a horizontal surface
__________________________________
