An investigation on padding pressure in football helmets
Materials required for this science fair project:
- A 2 meter long string
- 1 football helmet
- A 5kg circular weight (~100mm diameter) with a hole in the middle
- 1 bowling ball small enough to fit inside the helmet
- 1 air pump
- 2 pressure gauges1 air bag
- 4 bricks
- 1 chair
- An assistant
1. The independent variable in this experiment is the air pressure applied to the padding in the helmet. The dependent variable is the increase in the pressure inside the air bag on collision with the 5 kg weight, which is determined by measuring the maximum deflection in the air pressure gauge. The constants (control variables) are the height at which the weight is dropped , the mass and size of the weight, the size and brand of the helmet, the size of the air bag, and the initial pressure in the air bag.
2. Arrange the four bricks in a square and leave a small hole in the middle as shown in Figure 1. Place the bowling ball in this gap to prevent it from rolling.
3. Increase the pressure of the padding in the helmet to 750 mmHg using the air pump and pressure gauge. Do the same for the pressure in the airbag.
4. Place the airbag on top of the bowling ball with the pressure gauge still connected as shown in Figure 1. Place the football helmet over the airbag.
5. Instruct the assistant to stand on a chair and hold the 2 meter long string vertically with the bottom end touching the center of the helmet (point of impact). Insert the tip of the string through the hole in the 5 kg weight, and release the weight by letting it travel down the length of the string When the 5 kg weight has landed on top of the helmet, note the maximum pressure gauge reading and record it. Repeat the test for five times. Calculate the average pressure readings and record it in the table below.
6. Repeat step 5 after increasing the padding pressure in the helmet to 800 mmHg, 850 mmHg and 900 mmHg. Record the average readings in the table given below.
Caution should be taken to prevent the falling weight from hitting anyone