Forces and Elasticity Flashcards
Name the three ways in which the shape of an object can be changed
Stretching
Bending
Compressing
How can the shape of a stationary object be changed?
When more than one force is acting on the object
What force causes a spring to go back to its original shape after being stretched/extended?
Tension
Why is it that to change the shape of a stationary object, more than one force has to be applied?
Because if a single force acted on an object, it would simply cause the object to move
If an object returns to its original shape when the forces acting on it are removed, has it been deformed elastically or ineslastically?
Elastically
If an object does not return to its original shape after the forces acting on it are removed, has it been deformed elastically or inelastically?
Inelastically
What is elastic deformation?
When an object returns to its original shape when the forces applied to it are removed
What is inelastic deformation?
When an object does note return to its original shape after the forces applied to it have been removed
How do you calculate the extension of an object?
Extended length - Original length
How do you calculate the compression of an object?
Original length - Compressed length
What is the equation of Hooke’s Law?
Force = Spring Constant x Extension (or compression)
What is the symbol for spring constant?
K
What are the units of the Spring Constant
Newtons per metre
(N/m)
What are the units for extension?
Metres
(m)
What is the symbol for extension?
e
Extenstion is _ _ _ _ _ _ _ _ to the forces applied on an object
fill in the blank
Extenstion is directly proportional to the forces applied on an object
Extension is directly proportional to the forces acting on an object, provided that the _ _ _ _ _ _ _ _ _ is not exceeded
fill in the blank
Extension is directly proportional to the forces acting on an object, provided that the limit of proportionality is not exceeded
The work done on an object is _ _ _ _ _ to the elastic potential energy
The work done on an object is equal to the elastic potential energy
When is the work done on an object not euqal to the elastic potential energy?
When the object is inelastically deformed
What is the equation for elastic potential energy?
Ep= 1/2 x K x e^2
What is the limit of proprtionality?
The point beyond which the extension of a spring is no longer directly proportional to the force applied to it
Beyond the limit of proportionality, the stiffness of a spring decreases making it easier to stretch. Will this make an extension-time graph curve up or down beyond the limit of proportionality?
It will curve up
because as more force is applied, it will be alot more easier to extend so will extend more.
Describe the
relationship between the force and the extension when the limit of proportionality has been exceeded
[2 marks]
The relationship is non-linear
as the extension is no longer directly proportional to the force applied
