To find the acceleration of an object when falling down from a height in the presence of earth’s gravitational field, which is also known as free fall. Air resistance is neglected in this experiment.
THEORY
As an object is released from a height from the ground under the influence of the Earth’s gravitational force, the object will always fall under a constant rate of acceleration. Unlike in space, where object will just float around after being released, object falling on Earth will always be pulled towards the ground by gravity. Since the gravitational force of the Earth is always the same at a particular place, the object will fall with a constantly increasing speed, that is if air resistance is neglected. This acceleration is independent of the object’s mass or height; it only depends on the strength of the gravitational field.
RAW DATA TABLE PROCESSED DATA TABLE DATA PROCESSING GRAPH t²/s² AGAINST HEIGHT FROM GROUND h/m
JUSTIFICATION FOR UNCERTAINTIES AND CALCULATIONS 1) Uncertainty for metre rule * Half of the smallest division on the analog instrument
= 0.01m/2
=0.005m
2) Uncertainty for time taken * Smallest division on a digital stopwatch
=0.01s
3) Average time
= 0.74+0.75+0.773
=0.75s (for height=2.200m) 4) Uncertainty for average time
=(maximum time-minimum time)2
=(0.77-0.74)2
=0.015≈0.02 5) Calculation of T2/s2
=0.752
=0.56 (for height=2.200m) 6) Uncertainty for T2/s2
= (maximum T2-minimumT2)2
= (T+uncertainty of T)2-(T+uncertainty of T)22
=(0.75+0.01)2-(0.75-0.01)22
= 0.02s (for height=2.200m) 7) Gradients
Gradient of best fit line= 0.601
Max. gradient= 0.65
Min. gradient= 0.55 8) Uncertainty of gradient
=(max. gradient-min. gradient)2
= (0.65-0.55)2
= 0.05
Conclusion and Evaluation
From this experiment where the relationship between height/m and time/s is investigated
(by plotting a graph T2/s2