Springs and Hooke’s law
Before you start
Why does a stretched spring pull back, and what does its spring constant mean?
The setupA block slides on a frictionless horizontal rail, attached to a spring fixed to the left wall. x = 0 marks its natural length; right is positive. Hold mode includes the hand force; release mode removes it.
What to do and noticeAt equal deformation, what changes with a stiffer spring? · Does the block stop where the spring force is zero? · Where is the energy at the ends and in the middle?
Predict firstAt equal deformation, what changes with a stiffer spring?
Why does a stretched spring pull back, and what does its spring constant mean?
Prerequisites: A block slides on a frictionless horizontal rail, attached to a spring fixed to the left wall. x = 0 marks its natural length; right is positive. Hold mode includes the hand force; release mode removes it.Measure what k means
Predict firstAt equal deformation, what changes with a stiffer spring?
Hooke’s law is Fspring = −kx. k measures stiffness in N/m: 12 N/m means 12 N more force per metre of deformation within the linear range. The minus sign makes it a restoring force. While held, a hand supplies +kx to balance it, keeping the block still.
How to observe
- At equal deformation, what changes with a stiffer spring?
- Does the block stop where the spring force is zero?
- Where is the energy at the ends and in the middle?
Model notes
Massless Hookean spring within its linear elastic range; no damping or block rotation. Vertical weight and support cancel. Colours indicate elastic potential and kinetic energy, not temperature.