Forces Flashcards
If zero net force implies zero acceleration, is an object with zero net force always at rest?
Zero acceleration does not imply zero motion, simply indicates velocity is constant
What two forces act upon a book at rest on a table?
Normal force with the table (FN) and weight (Mg)
Normal Force always acts ____________ to the surface.
Perpendicular
What is Static Equilibrium?
When an object is at rest and remains at rest due to zero net forces
When will the magnitudes of forces subtract?
When the vectors occur in opposite directions (ie. South and North)
When will the magnitude of forces add together?
When the vectors occur in the same direction (ie. both North)
What is Hooke’s Law?
The length of a spring is directly proportionate to the applied weight; occurs when a mass is hung vertically from an elastic spring
What is the equation for Hooke’s Law?
F=-kx; k is spring constant (N/m)
On an incline, what is the equation for normal force (mass=M, angle=θ)?
FN= |Mgcosθ|
On an incline, what is the equation for the net force of the object (mass=M, angle=θ)?
ΣF=-Mgsinθ
What is Centripetal Force?
Inward force component (ie. tension of an object swinging in a cone)
What is the equation for centripetal force?
Fc=(mv^2)/R
What is Friction?
Contact force between two surfaces that is responsible for opposing sliding motion
What is the equation for friction?
Ff=μFN
What is an Ideal Spring?
A spring that follows Hooke’s Law: F=-kx
