Inquiry Physics Objectives

Links:

Content Standard I (Local):
Measurement

Topic:

4. Percentage difference and error
   Percentage difference and error show the discrepancy between two measurements or a measurement and a predicted result.

Time Range:
1 week for Standard I

Suggested Teaching Strategies:

• Show how to calculate each quantity, using “real-world” examples. Practice these techniques in various laboratories, having students decide which type of calculation is appropriate.
• Percentage difference is used when there is no theoretical value available; it is computed by dividing the absolute value of the difference between two measurements (or the highest and lowest measurement) by the average of those two measurements, and then multiplying by one hundred to obtain a percentage.
• Percentage error is used to compare theoretical and measured values; it is computed by dividing the absolute value of the difference between the measured and theoretical values by the theoretical value, and then multiplying by one hundred to obtain a percentage.

Aligned Resources:

• Core Lab 2: Vectors (percentage error)
  Inquiry Physics Investigation 2, Lab
• Core Lab 3: Forces and Acceleration Lab (distance vs. acceleration experiment; percentage difference)
  Inquiry Physics Investigation 5, Labs A & B
• Core Lab 5: Mass and Acceleration Lab (inventing F=ma; percentage errors)
  Inquiry Physics Investigation 6, Lab B
• Core Lab 8: Linear Momentum (percentage difference)
  Inquiry Physics Investigation 9, Lab A & B
• Core Lab 12: Ohm’s Law (percentage error)
  Inquiry Physics Investigation 15, Lab C

Revision Date:
December 2002