P2.3 Flashcards
explain the relationship between the force applies and the extension of an elastic object.
the extension is directly proportional to the force applied, provided that the limit of proportionality is not exceeded
what is meant by an inelastic (plastic) deformation
a deformation which results in the object being permanently stretched
the object doesn’t return to its original shape when the force is removed
what does the limit of proportionality look like on an extension-load graph
where the graph stops being linear
state the equation relating force, spring constant and extension
force (N) = spring constant (N/m) x Extension (m)
what is hookes law
states that force applied is directly proportional to the extension of an elastic object
at what point does hookes law no longer apply
the limit of proportionality
what type of energy is stored in a spring when it is stretched
elastic potential energy
what can extension be replaced with in the equation for spring force
compression
what is weight
the force that acts on an object due to gravity and the object’s mass
what is the equation for elastic potential energy
energy (J) = 1/2 x Spring Constant(N/m) x extension(m)^2
what type of field does all matter have
a gravitational field
how does the gravitational field of an object change as the object becomes more massive
the field strength increases
what is the unit used for weight
Newton (N)
what letter is used to represent gravitational field strength and what is its value at the surface of earth
g
the value of g on the surface of the earth is approximately 10N/kg
what quantities does weight depend on
the objects mass
the gravitational field strength at the given position in the field
what is the unit used for gravitational field strength
N/kg
what is the equation used to calculate weight
weight (N) = mass(kg) x gravitational field strength (N/kg)
what is meant by an object’s centre of mass?
the single point through which an object’s weight can be considered to act through
what is the acceleration of an object falling in free fall with no resistive forces acting
10m/s^2
why would your weight be different if you were on a different planet
the gravitational field strength varies for each planet
weight is the product of mass and gravitational field strength
what piece of equipment can be used to measure an objects weight
a calibrated spring-balance or newton-meter
what is an alternative name for the turning effect of a force?
a moment
state the equation used to calculate the moment of a force
moment of force (Nm) = force(N) x distance(m)
what distance measurement is used when calculating a moment?
the perpendicular distance from the pivot to the line of action of the force
