PASCO ME-6814 Mini Catcher Accessory - Manual (Page 13)

012-06293A Mini Catcher Accessory
9
Teacher’s Guide
Experiment 1
Hints for successful data collection (Part II):
• Be sure that the Mini Catcher is level and hanging close to, but not touching, the
Mini Launcher.
• Check to be sure the muzzle is aligned with the foam pad.
• Be sure the string moves freely in the Velcro assembly.
• Check to be sure the support plate is perpendicular to the table.
• To be sure any force exerted by the string attached to the Mini Catcher is mini-
mized, leave enough slack in the string to necessitate its being pulled only a few
centimeters at the top of the swing of the Mini Catcher.
• Be sure to tape the string to the Mini Launcher base after firing the Mini Launcher
and before measuring h.
• Be sure students are using for their velocity calculations in Part II the
∆
h of the
bottom of the Mini Catcher, not the absolute height above the table top of the
bottom of the Mini Catcher.
A Sample Data Set:
mass of steel ball = .016 kg
mass of Mini Catcher = .024 kg
ave.
∆
h = 0.16 m
y = 0.77 m
x = 1.8 m
v
0
(Part I) = 4.5 m/s
v
0
(Part II) = 4.4 m/s
K.E. before collision = 0.15 Joule
K.E. after collision = 0.063 Joule
Loss of K.E. = 58 %
Question 2:
The remainder of the K.E. was converted primarily to heat energy that was dissipated in
the foam pad. Other potential contributors to kinetic energy loss include torque in the
swing path of the Mini Catcher and potential energy in the elastic deformation of the
foam pad by the steel ball.