During this investigation, varying surface areas of objects will be explored in a manner observing the motion as they fall. Most predominantly, this motion encircles speed. Speed is calculated from the formula below, and hence is directly proportionate to time taken when the distance travelled remains a constant. Speed = Distance/Time surface area is likely to affect the time taken for an object to complete a descent, and therefore its speed during the descent, as higher surface area generally incurs a higher air resistance. Air resistance is derived from friction with gas molecules in the air, as the object collides with them.
By increasing the surface area of the object, more molecules are collided with; meaning a higher force of friction is put upon the object. During the object’s fall air resistance acts as an ‘upward’ force that works against the weight force – produced by the object’s mass. As surface area is the selected independent variable, weight will remain constant, meaning that the ‘downward’ force will also remain consistent. That said, the changing surface area will invoke a changing ‘upward’ force, thus implying that the resultant force will also change; making for a measurable relationship between surface area and speed of travel.
The Essay on Total Surface Area and Rate of Reaction
Antacid tablets are used to relieve heartburn and neutralise stomach acid. Planning Aim To determine how the surface area of the tablets affects the rate of the reaction. To determine which form of tablets gives the biggest surface area resulting in the fastest reaction rate. Investigation question: What is the relationship between the total surface area of the tablets and the rate of the ...
Factors of Investigation Surface Area – this factor was chosen to implement in the investigation as it is likely to exhibit an obvious set of results that are capable of representing a clear pattern in which a correlation could be easily obtained with the use of the causal link discussed in the introduction Weight – this factor was not chosen as changing the weight of an object can often affect the surface area substantially, therefore creating an unfair test of a single independent variable, as other uncontrolled variables would be present.
Nevertheless, a change in weight whilst maintaining a standard surface area could be achieved. This said, it was chosen not to use this factor of investigation as it was thought surface area would show a more clear pattern due to the wider range of results, and distance between results, that can be produced Density of the Medium – this factor was not chosen for two reasons. Firstly, the change of density within the same medium, such as air, would require the use of heating, making tests take longer and also incur the risk of burns.
As well as the fact that it would be much more difficult to implement into a fair test. Secondly, were media to be changed with density, the viscosities of each medium would act as an uncontrolled variable to the experiment, as viscosity and density are not necessarily proportionate, thus making results less clear and patterns less obvious. Hypothesis I believe that changing the surface area of the falling will affect the time at which is taken for its descent to be completed, and therefore also the speed at which it falls. Prediction
