Hooke's Law Flashcards

All 6 cards in this deck

State Hooke's law.

The extension of an elastic object is directly proportional to the force applied, provided the limit of proportionality is not exceeded.

Which equation links force, spring constant and extension?

$F = k e$ (force = spring constant × extension), with $F$ in N, $k$ in N/m and $e$ in m.

What is the unit of the spring constant $k$, and what does a large value of $k$ mean?

Newtons per metre (N/m); a large $k$ means a stiffer spring (more force needed per metre of extension).

What are the steps to calculate a spring constant from a force and an extension?

e.g. a force of $2.88$ N extends a spring by $1.50$ cm

1. Convert extension to metres: $1.50$ cm $= 0.015$ m
2. Rearrange $F = ke$ to $k = F/e$
3. $k = 2.88 / 0.015 = 192$ N/m

Does $F = k e$ apply to a spring being compressed as well as stretched?

Yes — $e$ is then the compression of the object instead of the extension.

True or false? The extension of a spring is the length of the spring while the load is attached.

False. Extension = loaded length − original (natural) length.