Capturing Your Physics Students’ Imagination Using a Football

There are some practical activities in physics that really help capture students’ imaginations and bring the theory to life. One great example marries physics with one of the nation’s favourite sports – football.

The practical involves students calculating the force used to kick a football and can be carried out in a number of ways (for more information and a full method see the Institute of Physics website http://practicalphysics.org/force-used-kick-football.html).

In one method the calculation is based on the length of time the foot is in contact with the ball and the distance the ball travelled. By assuming the ball is in free fall once kicked, the time of flight can be calculated using the vertical distance it falls. Once you have measured the horizontal distance the ball travelled, the horizontal speed of the ball can be calculated. In order to measure the duration of contact between the foot and ball, foil is taped to both the ball and the shoe of whoever is kicking. Crocodile clips are attached to the foil contacts, and used to trigger electrical timers. Your timer must be set up to start running when contact is made (between the foil on the shoe and ball) and stop when contact is broken. A number of our timers are capable of this function but it can be tricky to set up. We thought we’d eliminate the confusion and describe the set up for all our compatible timers here.
Fast Timer – B8H28573

Our Fast Timer is capable of microsecond timing, however, the contact is likely to be out of the range of this option so millisecond timing should be selected. The bias should be switched to “none” and the selector switched positioned to the left. The lead from the ball can then be connected to the 5V (red) reference socket, and the foot to the left hand side start/stop socket (blue). You are now ready to go!

S-Range Scaler-Timer – B8H28925

Setting up the Scaler-Timer is just as easy. Switch the Function to “timing” and the start/stop switch to “stop”. Switch on the mains and press the reset button to zero the display. The lead from the ball should be plugged into the start socket, and the lead from the foot into the black middle socket.

S-Range Digicounter – B8H29280

This timer operates in a similar way to the Scaler-Timer above, but with a few extra steps. The Function dial should select “timing”, and the ms range should be used. The “single reading” option next to the display must be selected, and the triggered timing switched off. As with the Scaler-Timer, then simply switch off the manual timing switch, turn on the mains and zero the display. Wire the ball to the start socket on the left, and the foot to the black middle socket.

If you have any further questions about using our timers with this or any other practical, please contact our Technical Support Team via techsupport@philipharris.co.uk