4. Discussion

 4. Discussion

4.1 Key findings & Analysis of results

The clay surface allowed the ball to bounce the highest, followed by concrete, wood, tile, turf and grass. The clay surface got the highest bounce instead of the concrete surface. Grass, as expected, lost 72 per cent of the energy, as the ball only bounced to 14cm from the dropping height of 50cm.

4.2 Explanation of key findings  

Clay surface can transport energy back to the ball from rebounce the easiest as the sound energy, and heat energy was the lowest. Grass lost a lot of power in the ball during rebounce to sound and heat energy the most, and since the surface cushions the ball a lot too.

4.3 Evaluation of Hypothesis

We expected the ball to bounce the highest on concrete the most due to it being a hard surface and the ball to bounce the least on the grass surface since it is softer than the other surfaces and will let the ball sink into it. When the surface is softer, the surface would usually absorb more energy from the ball, causing less kinetic energy when bouncing. 

4.4 Limitations and Areas for improvement 

The retort stand was too short for us to drop the ball from a 1m distance. We tried using a pipe, but the tube was too big, and the clamp could not clamp. Instead, we could have bought or made a bigger clamp, allowing us to drop the ball from 1m. 

We also had difficulty finding a proper material since the type of cardboard we used kept breaking or bending, resulting in the trapdoor breaking and not supporting the ball's weight. Instead, we used corrugated plastic cardboard as the material of the trapdoor. This was a suitable material to use as it does not bend as often and allowed us to use it as the trapdoor. Hence, we learned that we should have pre-tested materials to see how suitable it was before we started.

Next, we had a problem with our retort being taken apart and certain parts missing due to it being taken by other groups. This resulted in us needing to assemble the parts over and over again. This wasted a lot of precious time that we could have spent doing more important things. We learnt that we should have kept the retort stands and brought them back to class. This way, other groups will not be able to take the retort stands from our group.