Physics

Examining the Fall of a Foam Ball

In this class and the next you will create an excel model of projectile motion. We start with a simple model of a an object falling from a height and the continue to add more detail. Start by creating a sheet like the one below. I have created a simple formula to enable the time interval to be changed =B9+$E$5

The distance from the ground is found by determine the distance the object drops each interval using s = ut + 0.5at² and then adding to the original height. Remember we are interested in the height from the ground not how far it has fallen from the initial position. =$D$7+($E$4*B8+0.5*-9.8*B8^2)

What you will now notice is that a 1 second time interval is far too long if we are to get some meaningful data from our model. So change the time interval to 0.5s and drag down until you have covered 100 meters

To plot the fall of the object we will use the blank B column. As there is no horizontal displacement it stays at zero.

Changing the time interval to 0.5 of a second enables us to predict the object will take a little more that 4.5s to fall. but this is not exact. You should try to repeat this again with an even smaller time interval. This process of looking at smaller and smaller steps is called iteration and is an important process when developing a model.