Investigating the efficiency of a bouncy ball.
Aim:
Our aim was to investigate the relationship between the height released from and the height bounced when a ball is dropped.
Our aim was to investigate the relationship between the height released from and the height bounced when a ball is dropped.
Hypothesis:
I think that the ball will not return to the height is was dropped from because of the theory of conservation of energy. Energy is transferred when the ball is dropped from gravitational potential energy then it is transferred kinetic energy with the wasted energy being heat and sound energy. |
Context:
I think that you would use this physics in ball games. e.g. In tennis you have to estimate the height of which the ball which return to in order for you to hit in in the right place and not miss the ball completely.
I think that you would use this physics in ball games. e.g. In tennis you have to estimate the height of which the ball which return to in order for you to hit in in the right place and not miss the ball completely.
Method:
You can take your measurements by using your eyes but if you want a accurate measurement you could use slow motion cameras. I suggest that you take ALL your measurements in "cm" so you keep the experiment as fair as possible.
I think you need to take measurements from a reasonable distance above the floor. e.g. 40 cm - 200 cm.
Risk Assessment:
Do not throw the ball around in a lab (it can be dangerous by hitting people or other hazardous equipment)
Variables:
Controlled variables:
Independent variable:
The height of dropped tennis ball. This a categorical variable because the scale continues to go up an even number each time although it isn't a set number.
Dependent variable:
The height of the rebound from the ball. This is a continuous variable because it can change each time you change the height of the drop.
Results:
- You drop the ball from the correct drop height at eye level.
- You then drop the ball and record the rebound height. Try and take 5 readings for each height to make the experiment accurate.
- Find the average
- Repeat this for at least 5 average readings.
- Meter ruler
- Tennis ball
You can take your measurements by using your eyes but if you want a accurate measurement you could use slow motion cameras. I suggest that you take ALL your measurements in "cm" so you keep the experiment as fair as possible.
I think you need to take measurements from a reasonable distance above the floor. e.g. 40 cm - 200 cm.
Risk Assessment:
Do not throw the ball around in a lab (it can be dangerous by hitting people or other hazardous equipment)
Variables:
Controlled variables:
- The force which is used to drop the ball, just drop the ball do NOT put any force onto it.
- The placement of the ball, make sure the ball lands close to the ruler so you can get a more accurate reading.
Independent variable:
The height of dropped tennis ball. This a categorical variable because the scale continues to go up an even number each time although it isn't a set number.
Dependent variable:
The height of the rebound from the ball. This is a continuous variable because it can change each time you change the height of the drop.
Results:
Graph:
A graph to show the efficiency of a bouncy ball.
A graph to show the efficiency of a bouncy ball.
Conclusion:
From our results you can see that there is a clear correlation between the height of the drop and the rebound height. The higher you drop the ball the higher the rebound. These results do agree with my hypothesis, the gradient of the graph continues to rise at the same rate, this means the ball is more efficient because there is less energy transferred when the ball is dropped from a higher height.
From our results you can see that there is a clear correlation between the height of the drop and the rebound height. The higher you drop the ball the higher the rebound. These results do agree with my hypothesis, the gradient of the graph continues to rise at the same rate, this means the ball is more efficient because there is less energy transferred when the ball is dropped from a higher height.
Evaluation:
You may come across some inaccuracy but to prevent this you could use the latest slow motion cameras to get the most accurate result available. You could improve the investigation by doing this. I chose to use an increase of 40 cm each time because it is a good number to get a different result from in order to get a range of results.
You may come across some inaccuracy but to prevent this you could use the latest slow motion cameras to get the most accurate result available. You could improve the investigation by doing this. I chose to use an increase of 40 cm each time because it is a good number to get a different result from in order to get a range of results.
Calculations:
IN = mass (in kg) x gravity x height (in m)
OUT = mass (in kg) x gravity x rebound height (in m)
LOST = IN - OUT
40 cm:
IN = 0.05756 kg x 10 x 0.4 m = 0.23024
OUT = 0.05756 kg x 10 x 0.166 kg = 0.0955496
LOST = 0.23024 - 0.0955496 = 0.1346904 J
80 cm:
IN = 0.05756 kg x 10 x 0.8 m = 0.46048
OUT = 0.05756 kg x 10 x 0.352 kg = 0.2026112
LOST = 0.46048 - 0.2026112 = 0.2578688 J
120 cm:
IN = 0.05756 kg x 10 x 1.2 m = 0.69072
OUT = 0.05756 kg x 10 x 0.522 kg = 0.3004632
LOST = 0.69072 - 0.3004632 = 0.3902568 J
160 cm:
IN = 0.05756 kg x 10 x 1.6 m = 0.92096
OUT = 0.05756 kg x 10 x 0.722 kg = 0.4155832
LOST = 0.92096 - 0.4155832 = 0.5053768 J
200 cm:
IN = 0.05756 kg x 10 x 2.0 m = 1.1512
OUT = 0.05756 kg x 10 x 0.828 kg = 0.4765968
LOST = 1.1512 - 0.4765968 = 0.6746032 J
IN = mass (in kg) x gravity x height (in m)
OUT = mass (in kg) x gravity x rebound height (in m)
LOST = IN - OUT
40 cm:
IN = 0.05756 kg x 10 x 0.4 m = 0.23024
OUT = 0.05756 kg x 10 x 0.166 kg = 0.0955496
LOST = 0.23024 - 0.0955496 = 0.1346904 J
80 cm:
IN = 0.05756 kg x 10 x 0.8 m = 0.46048
OUT = 0.05756 kg x 10 x 0.352 kg = 0.2026112
LOST = 0.46048 - 0.2026112 = 0.2578688 J
120 cm:
IN = 0.05756 kg x 10 x 1.2 m = 0.69072
OUT = 0.05756 kg x 10 x 0.522 kg = 0.3004632
LOST = 0.69072 - 0.3004632 = 0.3902568 J
160 cm:
IN = 0.05756 kg x 10 x 1.6 m = 0.92096
OUT = 0.05756 kg x 10 x 0.722 kg = 0.4155832
LOST = 0.92096 - 0.4155832 = 0.5053768 J
200 cm:
IN = 0.05756 kg x 10 x 2.0 m = 1.1512
OUT = 0.05756 kg x 10 x 0.828 kg = 0.4765968
LOST = 1.1512 - 0.4765968 = 0.6746032 J