7. Introduction to Forces, Dynamics, & Newton's Law of MOtion Flashcards
Dynamics
Is the connection between kinematics and forces
Force
Is a push or pull; an action capable of moving an object; measured in Newtons.
Force also has a new unit known as the
Newton [N]
Newton’s First Law of Motion is also known as…
Law of Inertia
Law of Inertia
An object in motion remains in motion along a straight line path until an unbalanced force acts upon that object.
An object at rest remains at rest until a force acts upon that object.
Inertia
Tendency of an object to maintain its state of rest or uniform motion.
Mass
A measure of the amount of stuff of an object. (kg)
Weight’s Unit
Fg
Weight [Fg]
A force that represents the mass time gravity
Equation for Weight
Fg = mg
Newton’s Second Law of Motion is also known as…
[F=ma]
Newton’s Second Law of Motion [F=ma]
The acceleration of an object is directly proportional to the net force acting on it and is inversely proportional to its mass.
The direction of the acceleration is in the direction of the net force acting on object.
Symbol of Sigma
Σ
Σ [Sigma] means…
“The sum of”
Symbol of Net Force and what it means…
ΣF= (the sum of all the forces added together)
Hooke’s Law
“for relatively small deformations of an object, the displacement or size of the deformation is directly proportional to the deforming force or load. Under these conditions the object returns to its original shape and size upon removal of load.”
Spring constant
When an object is stretched or compressed by a force. The object exerts a force back that is equal to the distance stretched times something known as S…C…, but opposite in direction.
Explain Fspring= -kx
-k > Spring constant
x > Distance stretched
Can k be zero?
Technically No
Can k be negative?
NO!!!
Newton’s Third Law is also known as…
action-reaction
Newton’s Third Law [action-reaction]
Whenever an object exerts a force on a second object, the second object exerts an equal and opposite force in the first object.
“To every action there is an equal and opposite reaction”
Free Body Diagram
To analyze the forces on an object we start with this concept.
(this are the arrows indicating the forces upon the object)
Unit of Spring constant [-k]
N/M
Normal Force is represented by the symbol…
Fn
