practical skills Flashcards
why may using a computer and sensor be a more sensible option to obtain measurements
As the reading have to be taken more quickly than could be obtained by manual measurements
what is a hypothesis?
a scientific hypothesis is a suggestion,
prediction or untested idea.
Why is it important to test any new theory by testing it’s predictions experimentally
If test doesn’t provide supporting evidence prediction is incorrect
So theory is incorrect and just be changed
outline a method for the inversion tube experiment
.place a solid in a tube such as lead shot
.invert the tube a number of times around 50
.measure the temperature increase
.gain in internal energy is equal to loss of gravitational potential energy
.specific heat capacity is given by
c=gLn/T
L-length of tube
n-number of inversions
what causes systematic error
the enviroment,appartus used or experimental method
how do you reduce zero error
by callibrating apparatus by measuring a known value
how do you calculate the uncerntainty of the mean
find the range and half it
what is absolute uncertainty
the uncertainty of a measurement give as a certain fixed value
what is fractional uncertainty
the uncertainty given as a fraction of the measurement taken
what is percentage uncertainty
the uncertainty given as a percentage of the measurement taken
how do you add the percentage uncerntainties
by multiplying or dividing data
how do you add absolute uncertainaty
by adding or substracting data
what is uncertainty in a reading
+ or - half of the smallest division
what is uncertainty in a measurment
+ or - 1 of the smallest divisions
name 3 ways to reduce random error
preform repeats and calculate a mean
use computers or data loggers to reduce human error
use appropriate equipment
