How Do Things Fall?
How do things fall?Copyright http://upload.wikimedia.org/wikipedia/commons/d/da/Paratroopers_of_the_U.S._Army's_4th_Brigade_Combat_Team_(Airborne)_25th_Infantry_Division_parachute_over_the_Malemute_Drop_Zone_at_Joint_Base_Elmendorf-Richardson,_Alaska,_on_April_17,_2013_130417-F-LX370-462.jpg
Students learn that it is incorrect to believe that heavier objects fall faster than lighter objects. By close observation of falling objects, they see that it is the amount of air resistance, not the weight of an object, which determines how quickly an object falls.
Any difference in speed between two objects dropped at the same time is solely due to the resistance provided by air molecules hitting the objects as they fall. This drag factor is exploited by engineers as they design the aerodynamic shapes of race cars, bicycles, motorcycles, helmets, parachutes, boat paddles, scuba diving fins, darts, bullets, storm sensors and measurement devices, and medical devices, to name a few.
After this activity, students should be able to:
- Make predictions about weights and gravity.
- Understand that objects of differing weights fall with the same speed.
- Determining the velocity of an object based on time and height (V=D/T)
- Describe air resistance as counteracting the force of gravity.
- Understand how engineers use the drag factor as they design the aerodynamic shapes of race cars, helmets, parachutes and many other objects.