Lab Reports - 1100 Words

Lab Reports (Lab Report Sample) Content: Name Tutor Institution Date Lab ReportsIntroductionThe core purpose of conducting physics experiments in the laboratory in not only focused at reinforcing the materials learned in class, but also to enhance the understanding of the way scientific knowledge progresses. Experiments are conducted sometimes to prove whether there is harmony between the theoretical and practical parameters in physics. For example, it is known that the acceleration due gravity for a free fall near the surface of the earth is 9.8m/s2. However, practically this figure may not correspond to the theoretical one due to several underlying factors like errors incurred in performing the experiment. The purpose of these experiments is to learn how to use data for analysis in conversion of units, plotting of data, re-plotting data to obtain a straight line graph, finding the slope of a straight line graph, using the slope of the a graph to find a physical quantity and calculating percentage of error incurred while computing the figures and data for the results obtained. Experiments for the free fall and acceleration on a frictionless surface have been contacted and their results obtained as shown in the tables below. The principle of free fall is applied by parachutes when moving from a moving airplane. The parachute has some air sacks which trap air and offer some resistance to a free fall. Experiment 1: Freely falling base ballAn experiment for a baseball initially at rest, and falling straight down in air was contacted, the distance measured with an ultrasonic ranger placed above the ball and the results recorded in table 1 shown below.Table 1: Freely falling baseballTime, t (s)Distance from the detector (m)t2 (s2)Displacement, y (m)00.872000.100.9220.010.050.201.0610.040.1890.301.2870.090.4150.401.6350.160.7630.502.0790.251.207 The t2 and the displacement columns have been filled as shown above. The displacement is the distance of the bal l that it travelled from its initial position at t = 0.A displacement y (vertical axis) against time t (horizontal axis) was plotted as shown below (Graph 1). A graph of displacement y against time t2 was also plotted and the best fit line of the data drawn (graph 2 below). The slope of the graph can be computed as change in y/change in x. This gives as; Slope = 0.95 0.415 0.2 0.09 = 4.86 unitsGraph 1: displacent y(m) vs Time t (s)
Graph 2: Displacement y (m) vs Time t2 (s2)
4. The physical quantity that is represented by the slope of the graph is acceleration of the ball due to free fall (gravitational acceleration).5. The experimental value of g from the value of the slope can be computed from the relationship; y = 1/2gt2, this means that g = 2y/t2; g = 1.2*2/.25 Hence g = 9.6 m/s26. The percentage error is calculated as; (9.81 9.6/9.81) * 100%= 2.14%Experiment 2: Acceleration of a car under a constant forceThe experiment for the acceleration of a car on an air track (frictio nless surface) was contacted and the results obtained recorded in a table as shown below (Table 2). The units of the total mass were converted from grams to kilograms and the results recorded in the third column. The inverse of the mass (in kg-1) were also calculated and the figures were filled in the fourth column as shown in table 2 below.Table 2: Freely falling baseballTotal mass, m (g)Acceleration, a (m/s2)Total mass, m (kg)1/m (kg-1)5015.720.050201008.370.10102004.020.2054001.980.402.58001.030.801.2516000.471.60.625A graph of acceleration a against mass m was plotted as shown below (graph 3)
Graph 3: Acceleration a, (m/s2) vs mass, m (kg)A graph of acceleration, a, against mass m (kg) was also plotted and the best line fitted as shown below (graph 4)Graph 4: acceleration a (m/s2) vs. 1/m (kg-
The slope of the graph is calculated as; 8 4/10 5 = 0.8 unitsExperiment 3: The period of a pendulumThe period T of a pendulum is given by; T = 21/g, w here l is the length of the pendulum and g is the gravitational acceleration given as 9.80 m/s2. The experiment to determine acceleration due to gravity was conducted and the results were recorded in a table as shown in table 3 below.Length l, (m)Period ,T (s)T (s2)0.2000.910.830.4001.261.590.6001.582.500.8001.803.241.002.084.331.202.224.93The values for period squared were computed and their values filled in column 3 as shown a...