Summarize the investigations and reflect on these activities by leaving a comment to the this post on isklrobotics.blogspot.com:a) What is the Gear Ratio? Write out the formula to calculate it.
b) Write down the formulas for the two hypotheses.
c) Using GoogleDocs Spreedsheets, create a table like the one below to record your information for each of the tests.
• Make a link in your comment that points to the Spreadsheet you create in GoogleDocs. “Share” your GoogleDoc Spreadsheet with Mr. Inskeep and your fellow classmates.
• Perform condition 1 and record your information. You will not make a predicted speed for this.
• Use your data from condition 1 to make a predicted speed for condition 2 (hypothesis A and
B). Show your calculations for this.
• Perform the tests for condition 2 and record your data.
• Use your data from condition 1 to make a predicted speed for condition 3 (hypothesis A and B). Show your calculations for this.
• Perform the tests for condition 3 and record your data.
d) Make a conclusion about which hypothesis was correct.
3 comments:
Lately we have been learning about an important engineering tool that is used in almost anything with a motor: gears. A gear ratio is the ratio of the number of teeth on the driven gear over the number of teeth on the driving gear. A gear ratio of less than one will increase the speed of the robot but decrease the power, while a ratio of greater than one will decrease speed but increase power. In an investigation we did, we were given two hypotheses. Hypothesis A stated that speed 1 over gear ratio 1 equals speed 2 over gear ratio 2. Hypothesis B stated that speed 1 times gear ratio 1= speed 2 times gear ratio 2. In the end, we found that hypothesis A was not correct but hypothesis B was correct. The following link shows the table we made in the investigation that helped us disprove hypothesis A
http://1.bp.blogspot.com/_RzC8d1KUqj8/Sa_HcgJZv4I/AAAAAAAAABQ/rIZC7OPCluo/s1600-h/robotics+results+table.jpg
Gear Ratio is the ratio of driven gear, and driving gear. Driven gear is placed at the wheel side, and driving gear is placed at the motor side. Gear Ratio is represented by Driven gear/Driving gear.
Lets say that the Gear ratio is 1, and that speed is 20cm/s. If I change the gear, and increase the Gear ratio more than 1, then the speed of the robot will decrease (less than 20cm/s). Oppose to this, if the Gear ratio is less than 1, then the speed of the robot will increase (more than 20cm/s).
There are two hypothesis, made during the lab of Gear change. One of them calculates the
relationships of gear ratio and speed of the robot accurately.
Hypothesis A: (Speed 1 / Gear Ratio 1) = (Speed 2 / Gear Ratio 2)
Hypothesis B: (Sppeed 1 x Gear Ratio 1) = (Speed 2 x Gear Ratio 2)
https://spreadsheets.google.com/a/iskl.edu.my/ccc?key=pXv_UPq5jWQxB55viyDkUIA&hl=en
From the investigation and completing the spread sheet, I found out that the Hypothesis B is right.
The answers of two Hypothesis are totally opposite, and I knew that only one of them is right.
From comparing my experiments data, and theoretical calculations, the data of the experiment was much close to the answer of Hypothesis B.
Therefore, I found out that the Hypothesis B is the actual correct one.
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