General Important Practical Stuff Flashcards
How do we justify the number of significant figures used in a practical?
Should use the resolution of the measuring equipment
How do we estimate the difference in … using a graph?
Count squares
How do we justify if the results of an experiment are consistent with an equation?
Analyse the graph
e.g:
-straight line
-intercept is consistent
-passes through all error bars
-values used linked to values in equation
(e.g - using l for V in PV=nRT and V is proportional to T so straight line)
How would we get A=Aoe-kt in graphical form?
Take logs
How do we determine a value form a graph?
Gradient
how do we “justify” a claim?
Do calculations
% difference between 2 values
Calculates-actual/actual x100
What do we need to do when going from an equation to a graph?
Input the equation into the equation of a straight line
y = mx + c
How do we know which values to put where in the equation of a straight line?
Think…
What are the constants?
What are the variables (these will be x and y)
How do we go from having a graph to an equation?
- locate 2 well separated x and y points
- calculate the gradient
-can calculate c using y=mx + c
How can we work out the accuracy of a value?
Work out the uncertainty
Does the value fit into the uncertainty value?