You can guess.

What you will need To do this exercise, you will need the following tools - Something you can drop from a height (like a tennis ball - 3 balls is easy) - A fast timekeeping device like a stopwatch (built into many smartphones and watches) - String long enough to extend the distance to drop things - A yardstick, measuring tape, or something to measure the length of the string - Weights (e.g., metal washers) to tie onto the string - Markers to mark the string

1.1 Measuring Falling Bodies

It helps to have one person dropping items and one person doing the timing. Also, one person should be responsible for writing down the results - this can be one of the other two or a third person. Youshould gather the equipment described at the start of the lab.

Select the locations you will be dropping the objects from. These need to be places where you can safely drop these objects without hitting people or damaging property. You should try for a least 3 and up to 6 locations with different drop heights.

Estimate the amount of string you will need to extend from the highest location you will be dropping from to the ground, and cut a length at least this long. It's fine to have too much string but it gets complicated if you have too little.

Tie the metal washer to one end of the string so that it can hang straight down. Use the weighted string and a marker to mark on the string the heights of the stations you selected to drop your objects. Make sure the washer is barely scraping the ground as you mark the string.

After you have completed drops at all of your stations, measure the length of the string to each of the marks. Be sure to include the length of the washer in your measurement.

1. Below or on a separate page describe the largest sources of error in measuring the drop times and the length of the string. Also explain if these errors are systematic or random.

Table 1: Measurements Station Time 1~ Time 2+ Time 34 Height he Avg. Time Avg. Time Squared t1 (sec)