Physics – 1.5.1 Effects of forces | e-Consult

Experimental Procedure:

1. Materials: A small, lightweight object (e.g., a small piece of cardboard or foam), a controlled drop height (e.g., 1 metre), a measuring device (e.g., a stopwatch), a ruler or calipers to measure surface area, and a stand to ensure consistent drop conditions.
2. Procedure: Cut out multiple objects of the same shape but with varying surface areas (e.g., one with a large surface area, one with a medium surface area, and one with a small surface area). Drop each object from the fixed height, ensuring the drop is performed repeatedly (e.g., 5-10 times) for each surface area. Measure the time taken for each object to fall from the height.
3. Variables:

   • Independent Variable: Surface area of the object.
   • Dependent Variable: Time taken for the object to fall.
   • Controlled Variables: Drop height, initial velocity (ensure the object is released from rest), air conditions (e.g., conduct the experiment in a room with minimal drafts).

Analysis and Support for Friction (Drag):

The results of the experiment would show that objects with larger surface areas take longer to fall than objects with smaller surface areas. This is because the objects with larger surface areas experience a greater force of air resistance (drag). The drag force is proportional to the surface area of the object. The larger the surface area, the more air the object collides with, and the greater the opposing force. By controlling other variables, we can isolate the effect of surface area on air resistance, thus supporting the concept that friction (drag) is a force that opposes the motion of an object through a fluid (in this case, air). A graph of time vs. surface area would demonstrate this relationship.