Forces Flashcards
What does a scalar quantity have?
magnitude, for example, three apples.
What does a vector quantity have?
magnitude AND direction e.g 7mph north east
What features of arrows can represent vector quantities?
the length of the arrow can show the magnitude and the arrow points in the direction the vector quantity is acting.
When does a force occur?
when two or more objects interact
what are the groups of contact forces?
contact and non-contact
What are the non-contact forces?
gravitational force
electrostatic force
magnetic force
what are the contact forces?
friction air resistance tension upthrust normal contact force
What is a basic explanation for gravity?
a force of attraction between all masses.
what is the mass of an object related to?
the amount of matter it contains and is constant
what is the weight?
the force acting on an object due to gravity
what does the weight of an object depend on?
the gravitational field strength where the object is and is directly proportional to its mass.
What is a resultant force?
when more than one force acts on an object, these forces can be seen as a single force that has the same effect as all the forces acting together.
What counts as “work done on an object”? and why is this?
when a force causes the object to move, be cause it requires energy to move an object.
when is one joule of work done?
when a force of one newton causes a displacment of one metre.
what is displacement?
distance moved
what does more than one force applied to an object do to the object?
changes the shape of the object
what is the object called when the object returns to its original shape after the forces are removed?
elastically deformed
what is inelastically deformed?
when the object does not return to its original shape
what is the extension of an elastic object directly proportional to?
the applied force
what does it mean if the extension of an elastic object is directly proportional to the applied force?
they have a linear relationship and produce a straight line on a force-extension graph.
what happens when the limit of proportionality has been exceeded? –2
-doubling the force will not double the extension
-the relationship becomes non-linear
a force-extension graph will stop being a straight line.
what does it mean when it is past its limit of proportionality?
it becomes inelastically deformed
what is Hooke’s law?
the theory of elasticity–the extension of a spring is proportional to the force applied to it
what no longer applies once past the limit of proportionality?
Hooke’s law.
