Does Weight Matter?
Would there be more friction between the girl and the slide if she held a heavy bowling ball while sliding down?Copyright NSF
Using the same method for measuring friction that was used in the previous lesson (Discovering Friction), students design and conduct experiments to determine if weight added incrementally to objects affects the amount of friction encountered when they slide across flat surfaces. After graphing the data from their experiments, students calculate the coefficients of friction between the objects and the surfaces they moved upon, for both static and kinetic friction.
Engineers must understand how friction affects many situations, from the bottom of skis in which friction is a disadvantage to hiking boots where friction provides traction. Scientists must think like engineers when designing experiments, as students do in this activity.
After this activity, students should be able to:
- Explain that, for friction due to surface roughness, the frictional force is proportional to the weight of the object being moved across a surface.
- Calculate the coefficient of friction for an object whose weight and the measured frictional force between the object and a surface are given.