# Galileo Experiment on Motion

Galileo Experiment on Motion Investigatory Project

Aim

To study the first law of motion by the double inclined track.

Apparatus

Double inclined track, Metal ball, Glass plate of same thickness, Wooden block etc. The double inclined track apparatus consists of a pair of inclined tracks, each of them can be independently set at a small angle of inclination.

Theory

A body will continue its state of rest or uniform motion along a straight line unless an external resultant force acts on it.

Procedure

Set up the double inclined track on the table. Clean the metal ball and the track using cotton or tissue paper. Insert the wooden block under the right arm at such a position that the track is inclined at a suitable angle (nearly 45°) with the horizontal. Then left arm is arranged at a suitable angle of inclination. This is done by placing a number of glass plates below it (say 14). A point 'B' is marked on the right arm which is at a distance 10 cm from the lower edge. The metal ball is released from 'B' and the distance 'd' to which it ascends in the left arm is noted. The experiment is repeated for different angle of inclinations in the left arm. This can be done by changing the number of glass plates below it. Since the glass plates are of same thickness, the slope of the left arm will be proportional to the number of glass plates (n).

A graph is plotted with number of glass plates (n) along the X-axis and the reciprocal of the distance 'd' along the Y-axis. The graph would be a straight line. On extrapolating the graph to slope zero (ie, n=0), it is found that 1/D is nearly zero or d = ∞, which implies that the body will continue its motion along a straight line. This verifies the validity of the first law of motion.

Observations and Calculations

 Trial No: of glass plates below the left arm (n) Distance of ascend along the left arm (d) 1/d 1 2 Mean (d) - - cm cm cm cm-1 1 2 3 4 5 6 14 12 10 8 6 4

Report

This experiment verifies that in the absence of an external force, a body in uniform motion would continue its motion indefinitely along a straight line.