sources of errors & improvements

Question 1

reaction time in starting and stopping the stopwatch may result in values of t being inaccurate

Answer 1

repeat the experiment twice and use the average value of t to reduce random errors

Question 2

it is difficult to determine the start and end positions of each oscillation and hence, accurately count the number of oscillations

Answer 2

use a fiducial line to identify the lowest point of the oscillation in order to keep track of oscillations accurately

Question 3

the path of the pendulum bob is elliptical and not along a single plane

Answer 3

check that the oscillations are not elliptical by observing them from an angle perpendicular to the plane of oscillation

Question 4

some of the GPE is lost to the surroundings

Answer 4

use a smooth PVC tube instead of 2 metre rules on a plank

Question 5

the volume of cuboid may not be determined accurately as the plasticine is not a perfect cuboid; edges of the cuboid are not distinct and lengths measured using a ruler may not be precise

Answer 5

the volume of cuboid can be determined using a measuring cylinder by displacement method; shape the cuboid edges to make the lengths more distinct

Question 6

there is only one value of q obtained and thus the mass value may not be accurately calculated

Answer 6

repeat the experiment twice and use the average value of q to reduce random errors