Slow the Cylinder: Experimenting with Shock Absorber Springs
The springs in shock absorbers provide more comfortable rides for passengers.Copyright Oak Ridge National Laboratory http://www.ornl.gov/info/ornlreview/v32_2_99/driving.htm
Students learn why shock absorbers are necessary on vehicles, how they dampen the action of springs, and what factors determine the amount of dampening. They conduct an experiment to determine the effect of spring strength and port diameter on the effectiveness of a shock absorber. Using a syringe, a set of springs, and liquids of different viscosities, students determine the effects of changing pressures and liquids on the action of a model shock absorber. They analyze their data through the lens of an engineer.
Thanks to engineers, springs have been used to soften the ride for passengers since the days of horse carriages. As automobiles came into existence, the greater weight and speed of our vehicles required that the bouncing action of springs (oscillation) be controlled. Shock absorbers were invented to control the vertical acceleration of the wheels as they traveled over road bumps. As research evolved, engineers found ways to fine tune the amount of spring dampening to match the vehicle to the road conditions and its intended use. And vehicles are not the only use for shock absorbers! Engineers design buildings in earthquake zones to include a type of absorber that reduces damage (to people or sensitive scientific equipment, for example) when the ground shakes.
After this activity, students should be able to:
- Explain the purpose for a shock absorbing device on vehicle suspensions.
- Describe the variables that affect the dampening ability of shock absorbers.