U4 - Materials
What is Hooke’s Law? Provided the limit of proportionality is not exceeded, the extension of
a spring/wire ∝ the force applied.
The graph of load against extension of a spring obeying Hooke’s Law
will have a line of constant gradient passing via the origin. These are
two features.
What is the equation for
Hooke’s law in series and
why?
There is a force of Mg pulling on BOTH springs ⇒ overall extension is
double (as there are two springs) ⇒ the overall spring constant has to
𝑘
be2.
On the load-extension graph, you have a greater extension on the
equivalent spring for less force so the line is shallower. You can think
of this as a longe bungee rope stretching more than a shorter one.
How does Hooke’s Law work
on springs in parallel and
The same force of Mg is shared between both springs ⇒ extension on
why?
each is ½ the original ⇒ spring constant has to be 2k.
On the load-extension graph, you’re getting half the extension for the
same force so the line is steeper. You can think of this as using muscle
building equipment using multiple parallel springs, the more springs,
the harder it is to compress (and hence stiffer).
What is Hooke’s Law? Provided the limit of proportionality is not exceeded, the extension of
a spring/wire ∝ the force applied.
The graph of load against extension of a spring obeying Hooke’s Law
will have a line of constant gradient passing via the origin. These are
two features.
What is the equation for
Hooke’s law in series and
why?
There is a force of Mg pulling on BOTH springs ⇒ overall extension is
double (as there are two springs) ⇒ the overall spring constant has to
𝑘
be2.
On the load-extension graph, you have a greater extension on the
equivalent spring for less force so the line is shallower. You can think
of this as a longe bungee rope stretching more than a shorter one.
How does Hooke’s Law work
on springs in parallel and
The same force of Mg is shared between both springs ⇒ extension on
why?
each is ½ the original ⇒ spring constant has to be 2k.
On the load-extension graph, you’re getting half the extension for the
same force so the line is steeper. You can think of this as using muscle
building equipment using multiple parallel springs, the more springs,
the harder it is to compress (and hence stiffer).
