Points of Emphasis
There are two goals in this lab:
The first is to study the relationship between the size of a crater and the kinetic energy
of the projectile that forms it.
This is done by dropping steel balls of various diameter and mass from various heights into a
bowl of blasting sand. The diameters of the resulting craters are measured and correlated with
the kinetic energy of the projectiles when they struck the sand. To make the data taking
managable, individual lab groups are assigned specfic size balls and the class data is pooled.
The second is to introduce techniques for handling the error analysis of experimental data.
Topics introduced include: (1) types of errors (random, systematic errors, etc.), (2)
estimation of uncertainty in experimental data, and (3) simple mathematical techniques
(mean, standard deviation, etc.) for determining the total uncertainty in a derived result.
Introductory: P3, P13, P15
Number of set-ups available: 20
Per lab station:
1 tray to hold small items
4 steel balls of various sizes
1 6" ruler
1 tupperware container/sand
1 small lamp
1 2m meterstick
1 poster board cone
1 roll of masking tape
1 vernier caliper
1 extension cord
1 large rod
2 ring stand clamps
2 three-pronged clamp