# Experiment 2: Kinematics of Human Motion

Pages: 5 (1313 words) Published: September 14, 2012
Experiment 2: Kinematics of Human Motion
Laboratory Report

Leopoldo Luis A. Gueta, Lady Lian Lagamayo, Val Ian Caleb Leus, Kimberly Anne C. Macarilay Department of Math and Physics
College of Science, University of Santo Tomas
España Street, Manila Philippines

Abstract
Kinematics is the branch of classical mechanics that describes the motion of bodies and systems without consideration of the forces that cause the motion. There are four activities done in this experiment. Graphical analysis of human motion, where displacement vs. time and velocity vs. time were graphed. Graphical analysis of motion where in the 10th seconds the total displacement is 6.31m, average velocity is 0.628 m/s and instantaneous velocity is 1.257m/s. Reaction time where one of the normal reaction time among the group is 0.192s and the reaction time while someone is distracting the member is 0.175s, and lastly graph matching. 1. Introduction

All of us have the ability to move. Knowing how to describe motion is an important first step in understanding the underlying physics that governs changes in motion. We see changes in motion all the time, as we go to work or school, participate in sports or even wander around our homes. If we never changed our own motion, we would never make it out of bed in the morning. The study of motion and of physical concepts such as force and mass is called Dynamics. Kinematics is one of the topics under dynamics. Kinematics describes motion without regard to its causes. In this experiment, kinematics focuses in one dimension: a motion along a straight line. This kind of motion, involves velocity, displacement, and acceleration with regards to time. The objectives of the experiment are to draw the displacement versus time graphs and velocity versus time graphs for uniform motion and uniformly accelerated motion, and to determine one’s normal reaction time and his reaction time while being distracted by others. 2. Theory

The theory behind the experiment is all about graphical analysis of motion. There are two graphs that are often used: position vs. time and velocity vs. time. The following formulas have been used in the experiment: Ave. Velocity = total distance/time

Instantaneous velocity = 2 x Ave. Velocity
Reaction time formula = 2hg
Where:
h - Distance the meter stick has fallen measured from 50cm mark to where you catch it
g – 9.8 m/s²
3. Methodology
The first activity is about graphical analysis of human motion. The group predicted and sketched graphs namely: 1) Displacement vs. time and velocity vs. time - person is moving away with a constant velocity for 10s 2) Displacement vs. time and velocity vs. time - person is moving towards a starting point for 10s 3) Displacement vs. time and velocity vs. time - person is moving away from a starting point with increasing speed for 10s The second activity is about graph matching. The group created a graph which is the same as the position vs. time graph and velocity vs. time graph through moving in such a way that the graph of the motion matches the graphs using the Vernier Logger Pro. The third activity is about graphical analysis of motion. Using a meter stick, the distance travelled by one of the group members every second for 10 seconds was measured. Data such as the displacement, velocity, and instantaneous velocity, which is twice the velocity, were recorded. Based on the recorded data, a displacement vs. total time graph was plotted on the cross-section paper.

The last activity is about reaction time. One of the members of the group held a meter stick vertically and the other positioned his thumb and index finger (without touching the meter stick) at the 50cm mark. The group mate dropped the stick without telling the other member and the stick is caught with the thumb and index finger. The procedure is done twice for each member; one when in focus, the other when being distracted. The reaction time was computed using the data obtained. 4....

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