Forces Flashcards
what is a helical spring
the extension of the spring is directly proportional to the load (force applied)
what is the limit of proportionality
the point at which a spring stops obeying Hooke’s law
what is hookes law
the extension is directly proportional to the force applied
the is the equation of a spring constant
F = kx (k is the spring constant
what is the difference between elastic stretching and plastic stretching
-Elastic stretching will return to its original length
-plastic stretching will not return to its original length, it is permanently deformed
what is newtons first law
an object at rest will remain at rest, and an object in motion will remain in motion at the same speed unless acted on by a force
what is newtons second law
when there is a force acting on an object, it will accelerate with acceleration directly proportional to the force
what is newtons third law
every reaction has an equal and opposite reaction
equation for acceleration
a = (v-u)/t
equation for Force
F = ma
what is resultant force
the sum of all the forces acting on a body
what is terminal veolicty
-when gravity becomes equal to air resistance
what does air resistance depend on
-speed relative to air
-size/shape of the object
what is the maximum acceleration of an object if it is dropped on earth
10m/s squared
explain a graph question of terminal velocity (5 marks) memorise
-there is a resultant force
-it accelerates
-air resistance and friction increases as speed increases
-so acceleration decreases
-eventually air resistance + friction = driving force (forces are balanced)
-hence resultant force is zero
-object travels at a constant speed (terminal velocity)
