Physics help please - Sources of error in lab experiments

[Shordaay]

Physics help please -- Sources of error in lab experiments

Ok so i need some help with a few labs.. some I've tried out and a few i just can't get.. what i want to know is whether the limitations and sources of errors that i wrote down for each of these labs are correct or not and what i could have said instead. Thank you for your help in advance.

Sources of errors for center of gravity of an irregular shaped object:
-environmental error: when the wind blows it may remove the irregular shaped object from equilibrium.
- (i couldn't think of a next one)

sources of errors for density column:
- parallex error: when pouring the liquid into the container, the container should be on a flat surface and poured with eyes at an eye level or at 90 degrees.
- do not pour liquids along the side of the container to avoid mixing

limitations for density column:
-pouring should be gentle to avoid the mixing of the liquids
- try tilting the container a little so that the liquid you are adding runs down the side more slowly

sources of errors for rate of conduction of heat in copper, nickel, tin, brass and aluminium:
-human reaction time error: was slow when timing the exact time the match stick fell
- mechanical error: electrical glitches when using the stop watch

sources of errors for thermal expansion of ball and ring:
- mechanical error: electrical glitches when using the digital vernier caliper
-(i could not think of another one)

 

[Naty1]

Sources of errors for center of gravity of an irregular shaped object:
-environmental error: when the wind blows it may remove the irregular shaped object from equilibrium.
- (i couldn't think of a next one)

add: density variations, shape variations 'say, thickness], in ability to measure precisely, inability to compute precisely...

sources of errors for density column:
- parallex error: when pouring the liquid into the container, the container should be on a flat surface and poured with eyes at an eye level or at 90 degrees.
- do not pour liquids along the side of the container to avoid mixing

add: density varies slightly with height, with temperature, with atmospheric pressure,

limitations for density column:
-pouring should be gentle to avoid the mixing of the liquids
- try tilting the container a little so that the liquid you are adding runs down the side more slowly

sources of errors for rate of conduction of heat in copper, nickel, tin, brass and aluminium:
-human reaction time error: was slow when timing the exact time the match stick fell
- mechanical error: electrical glitches when using the stop watch

add: impurities in metals, measurement instrument variations, different ambient temperatures,varying ambient temperatures, thickness/size of metals,

sources of errors for thermal expansion of ball and ring:
- mechanical error: electrical glitches when using the digital vernier caliper

variations in temperature of heat source...location of ball ring wrsp to heat source; cooling while measuring, ambient condition variations,

 

[Shordaay]

thank you very much for your help.. by the way are those i came up with okay?