MECHANIC DEFINITIONS Flashcards
Definition of mass
amount of matter in an object
Newton’s 1st Law
An object continues in uniform motion in uniform motion in a straight line or at rest unless a resultant external force acts
Newton’s 2nd law
the resultant force on an object is proportional to the
acceleration (assuming mass is constant)
Newton’s 3rd law
for every action there is an equal but opposite action on another object
Definition of power
rate at which work is done or energy is transferred
Definition of projectile
an object moving through the air under the influence of only one force, gravity
Definition of speed
rate of change of distance
Definition of resultant force
the sum of all the forces acting on an object
Definition of spring constant
a measure of the force required to stretch or compress an object
Definition of static friction
the friction between two surfaces where there is no relative motion
Definition of terminal velocity
maximum speed attained by falling object, occurs when the downwards weight force is balanced by the upwards air resistance force
Definition of translational equilibrium
when the forces acting on an object are balanced
Definition of velocity
rate of change of displacement
Definition of weight
force of gravity acting on an object
Definition of work
a transfer of energy due to a force moving an object through a displacement
Definition of acceleration
rate of change of velocity
Definition of average speed
speed over a period of time (total distance / total time)
Definition of displacement
distance travelled in a particular direction
Definition of drag
frictional force due to a fluid
Definition of dynamic friction
friction between two surfaces where there is relative motion
Definition of efficiency
ratio of work or energy or power output to input
Definition of elastic collision
a collision where kinetic energy is conserved
Definition of energy
the capacity to do work
Definition of force
a push or a pull
Definition of free body diagram
diagram drawn to show all the forces acting on an object
Definition of impulse
change in momentum
Definition of inelastic collision
a collision where kinetic energy is lost
Definition of instantaneous speed
rate of change of distance at one particular time
law of conservation of
momentum
the total linear momentum of a system remains constant provided no resultant external force acts
Definition of linear momentum
product of mass and velocity
