This is a group activity that tackles the question ‘how far do balls roll on artificial pitches compared with natural grass?’ This could be a complex and wide ranging question and so will be paced down to the activity of designing and building a rig to launch a ball to roll across the pitches. The design requirements are that it is portable, durable (repeat tests in winter, spring and summer), not too costly (materials will be provided) and completed in the timescale. The tests will depend upon the sport chosen but would include distance, accuracy and ball condition – testing would be carried out on the same day for both pitch types to reduce weather variation effects.
The sports chosen are those where ball rolling takes place and also cover several of the sports in which the students participate so they can relate sports and materials. The sports offered are
These would then cover a range of materials and effects, e.g. water absorption, wear of ball, so that the launcher design will need different requirements. The balls are also different sizes and masses influencing the material choice.
Session 1 (MIT Lecture)
Sorting into groups to start discussion of problem definition of parameters
Group with tutor talk through design, e.g. pendulum vs ramp, what is to be measured, calculation of potential and kinetic energy. Initial design drafted out.
Lab class. Bending moments gone through (equation given), weighing of balls, sorting through material choices (PVC, guttering, aluminium, stell etc. will be provided along with frame building equipment and fasteners) and initial mass, deflection calculations made. Group member nominated as assessor to agree assessment criteria for launchers.
Prototype building, get balls.
Prototype testing, design modification and rebuilding.
Measurement day (pitches and weather permitting) launcher assessment and measurement of distances for several tests on each ball and several balls of the same design.
Data analysis (statistics and Excel) and web/page poster preparation
Completion of web page/poster
Create a web site and accompanying poster on the study. This should cover the design process, theory involved, methodology, results and conclusions. For tips on how to create an effective poster click here.
The winning launcher will be put on display along with posters, whilst web pages will incorporated into the Department web site.