Practical Skills Flashcards
What is the dependent variable ?
What is measured along the y axis
What is the independent variable ?
The variable we change
What do the control variable ?
The variable that must be consistent during the experiment
What is a measurement error ?
The difference between a measured value and the true value of the quantity being measured
What are two types of errors ?
Systematic and random
What is a systematic error ?
Errors that produce the same uncertainty in the experimental results . Affecting the accuracy of the results ( changes the intercept )
What is a random error ?
Errors that produces different uncertainties on the experimental results ( changed both the gradient and the intercepts of a graph
How can the percentage uncertainty be reduced ?
- larger values or a device with a greater resolution
How can you reduce random errors ?
By taking repeated measurements until the value is concordant
Removing anomalies
Calculating the mean
How can you reduce systematic errors ?
Change the experimental technique or resetting the devices
What is precision ?
How close are measurements are to eachother
What is accuracy ?
How close the measurement is to the true value
What is the absolute uncertainty
The measurement above and below the true value
What is the percentage uncertainty ?
The absolute value / measured value * 100
What happens to the uncertainty when you add two values ?
You add the absolute values together
What is the absolute value when something is measured to the nearest cm ?
The absolute value is +- 0.5 cm
What happens to the uncertainty when you divide two values ?
You are the percentage uncertainty
