kinematic and dynamic Flashcards
(28 cards)
average speed
the total distance travelled by an object divided by the total time taken
instantaneous speed
the speed of an object measured over a very short period of time
displacement
the distance travelled in a particular direction; it is a vector quantity
vector quantity
a quantity with both magnitude and direction
scalar quantity
a quantity with magnitude only
velocity
an object’s speed in a particular direction; it is a vector quantity
acceleration
the rate of change of an object’s velocity; the unit of measure is ms^-2
constant acceleration
when the change in velocity of an object is the same in the same time period
tangent
a straight line that touches a curve but does not cross it at a point
free fall
when an object accelerates due to gravity in the absence of any other force such as air resistence
component
the effect of a vector along a particular direction
Newton’s second law of motion
resultant force is proportional (ore equal) to mass x acceleration
inertia
a measure of how difficult it is to change the velocity of an object, or change its speed or direction. It is a measure of the mass of an object; a massive object has large inertia
weight
the force on an object caused by a gravitational field acting on its mass
friction
a resistive force when two surfaces are in contact and tending to slide over one another
uniform motion
the natural state of motion of an object-uniform velocity, constant speed and direction
Newton’s first law of motion
an object will remain at rest or in a state of uniform motion unelss a resultant force acts on it
resultant force
the single force that has the same effect as all of the forces acting on an object
terminal velocity
the maximum velocity reached by an object falling under gravity or accelerated by a constant force
resistive force
a backwards force in the opposite direction to movement caused by fricton or some other viscous force
drag
a force that resists the movement of an object through a fluid
contact force
the force at right angles to a surface when two objects are in contact
upthrust
the force upwards in a liquid or gas caused by the pressure in the gas or liquid
Newton’s third law of motion
when two bodies interact, the forces they exert on each other are equal size and opposite direction
