Physics Ch. 4 test retake; Forces and the Laws of Motion Flashcards
The state in which the net force on an object is zero.
equilibrium
A force that acts on a surface in a direction perpendicular to the surface.
normal force
The force that binds together atoms and molecules.
electromagnetic force
The force that slows down falling objects.
air resistance
The force that resists initiation of sliding motion between two objects.
static friction
Occurs when Fg=Fr
terminal speed
the weakest of the four fundamental forces.
gravitational force
This force binds protons and neutrons into nuclei
strong nuclear force
It opposes the movement of two surfaces that are sliding over one another.
kinetic friction
The force involved in beta decay, a type of radioactivity.
weak nuclear force
In general, Fnet equals
∑F
if Fnet ≠ 0 then, a ≠ ___
also this indicates the speed is anything but zero
a ≠ 0 as well since this means the acceleration can not be equal to zero and the object is being accelerated
if a nonzero force is acting on an object, then the object is definitely
being accelerated
a car goes forward along a level road at constant velocity. the additional force needed to bring the car into equilibrium is
zero,
*** this is because the car is already at equilibrium since it is traveling along a level road at a constant velocity.
A free-body diagram of a ball falling in the presence of air resistance would show;
a downward arrow to represent the force due to gravity and an upward arrow to represent the force of air resistance.
