Falling Objects and Air Resistance Lab Report Example | Topics and Well Written Essays - 500 words

Falling Objects and Air Resistance - Lab Report Example Fr = – cv, where coefficient c is called the damping constant. Thus the total of the forces acting on an object falling through atmosphere in a homogeneous field of gravity, moving only along the vertical axis, is expressed as F = Fr + Fg. All forces and velocities are considered positive when acting in the up direction and negative otherwise. Force of gravity equals Fg = – mg. According to Newtons second law, the force acting on an object compels it to move with an acceleration equal that force divided by the objects mass, i.e. a = . Acceleration is defined as the first derivative of velocity by time. Therefore we have In the lab, various combinations of coffee filters were used as experimental objects falling on the ground from a predetermined height x0 = 2m. Time needed for the object to reach the ground was determined as an average from 14 to 15 readings obtained by repeating the experiment, as summarized in tables 1 to 5. Because various combinations of coffee filters share their approximate shape and size, it seems reasonable to presume them to have the same value of c, so that their p values would be inversely proportional to m. If time needed for a falling object to reach the ground is determined by experiment, we can use equation (12) to determine the parameter p, in the following manner. Because x = 0 when object hits the ground, we have The left side of equation, L(p) = , describes a parabolic curve, the right side describes a descending exponential curve, with p as their common argument. We solve the nonlinear equation by finding the crossing point of these lines numerically, as resolved in enclosed excel sheet. Results are presented in Table 7 and Graph 9. Values obtained by measurement clearly depend on the type of object, with times decreasing as object mass increases (see tables at the end of paper). This proves air resistance has a significant effect for

Online trust in Singapore context Assignment Example | Topics and Well Written Essays - 1250 words

Online trust in Singapore context - Assignment Example 8 (a). The table below shows Spearman correlation analysis between â€Å"good product guarantees† and â€Å"products arrive in good condition†, where the rows represent the respondents’ opinions in good services and the columns represent the frequencies of the respondents structured answers in relation to the opinions. 8 (b). The table below represents spearman correlation analysis between â€Å"security information explained† and â€Å"safety of credits cards guaranteed†, where the rows represent the respondents’ opinions in good services and the columns represent the frequencies of the respondents structured answers in relation to the opinions. 8 (c). The table above shows spearman’s correlation between â€Å"uses of personal details explained† and â€Å"personal details kept confidential† where the rows represent the respondents’ opinions in good services and the columns represent the frequencies of the respondents structured answers in relation to the opinions. The 8 (eight) tables above are frequency tables that represent various variables analysed in question 10 of the survey. The variables are ‘Agree’, ‘Number of respondents’, ‘Disagree’, ‘Not sure’, ‘Strongly Agree’, ‘Strongly Disagree’, ‘skipped’ and ‘Total number of Respondents’. 10. The table below shows Spearman correlation between, â€Å"Whether the website looks and works generally the same as other online stores† and â€Å"The whole website experience is normal and without any unexpected situations (e.g. the appearance of pop up ads)† where the rows represent the respondents opinions as regards their trust in an online store and the columns represent the extents and frequencies of the respondents structured answers in relation to their reasoned levels of trust. 12 (a). The table below shows Spearman correlation between â€Å"presence of forums in the online store for you to check and discuss issues with other customers’’ and â€Å"if users post incorrect