Basics and Terminology 2 Flashcards
Action (push or pull) upon a body causing it to deform or move =
force
Force is measured in what?
newtons
Force is a _____ quantity.
vector
Force =
Mass x acceleration
_____ and ______ are most important in adjusting.
Speed and tension
Newton’s first law of motion is aka:
Law of inertia
The resistance to having its state of motion changed by application of force is called what?
inertia
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by and unbalanced force.
Newton’s 1st Law of Motion/ Law of Inertia
A system in equilibrium is either _____ or _____.
At rest
Moving with a constant velocity.
Newton’s 2nd Law of motion aka
Law of Force and Acceleration
The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object.
Newton’s second Law/ aka
Law of Force and Acceleration
What is a visual to help with Newton’s 2nd law. (inversely related to mass)
Person pushing a basketball and pushing a car. Same force, basketball moves, car does not.
Newton’s Third Law of Motion aka
Law of Action and Reaction
For every action, there is an equal and opposite reaction.
Newton’s 3rd Law, law of action and reaction.
Every action force is met with and equal and opposite reaction force. Does every ACTION produce and equal and opposite reaction?
No (b/c of second law)
Force always comes in pairs =
Equal and opposite action-reaction force pairs
A girl on skates vs. a girl on floor with shoes throwing a ball. Which law does this help show?
3rd Law
The intensity of force perpendicular to the surface on which it acts is called what?
Normal stress
The intensity of force parallel to the surface on which it rests is called what?
Shear stress
This exists when two contacting surfaces are not currently sliding relative to each other but do possess the POTENTIAL for movement.
Static friction
The ratio required to initiate a sliding motion between two bodies is called:
Coefficient of (static) friction
0.0 coefficient of friction is:
frictionless
1.0 coefficient of friction is:
Maximum friction
Friction in cases when the two surfaces are already sliding relative to each other:
Kinetic friction
Kinetic friction aka:
Dynamic friction
As soon as the applied parallel force exceeds the static friction force and the object begins to slide, what happens to the friction force?
decreases
When forces are exerted and objects are in contact what else is important?
pressure
The magnitude of applied force acting over a given area. (F/A=)
pressure
Pressure is measured in what?
Pascal (Pa)
Maximum stretch a material can withstand without rupture is called what?
Tensile strength
What is the tensile strength of skin?
9.25 N/mm2
Performed when an object is displaced by the application of force.
work
Work is measured in :
joules
If the object is not displaced was any work performed?
no
The energy an object possess due to motion.
Kinetic energy
Car 1 is stopped and Car 2 hits car one. Which car performed work? Why?
Car 2
b/c force was applied by Car 2 to make Car 1 move.
Since velocity is squared in the equation for kinetic energy what does that mean?
Changes in velocity have large effects of kinetic energy
