PASCO ME-9429B 1.2 m Classic Dynamics System - Manual (Page 29)

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M o d e l N o . M E - 9 4 2 9 A E x p e r i m e n t 9 : C o n s e r v a t i o n o f E n e r g y
29
Experiment 9: Conservation of Energy
Purpose
In this experiment, you will determine the spring constant of a compression spring
and use the spring to launch a cart up an incline. You will compare the potential
energy initially stored in the spring to the maximum gravitational potential energy
achieved by the cart.
Theory
The spring constant of a spring is
(eq. 1)
where F
x
is the force applied to the spring and x is the distance by with it is com-
pressed.
The potential energy stored in a spring is
(eq. 2)
The change in gravitational potential energy of a cart moving up an inclined track is
(eq. 3)
where m is the mass of the cart, g = 9.8 m/s
2
,
s is the distance traveled along the
track (in the uphill direction), and
 is the track’s angle of incline.
Required Equipment from Dynamics System
Track with Feet and End Stops
Cart
Pivot Clamp
Spring Cart Launcher (with a spring and release pin)
Super Pulley with Clamp
Other Required Equipment Suggested Model Number
Base and support rod ME-9355
Mass hanger and mass set ME-9348
Graph paper
String (40 cm)
k
F
x
x
------ =
Spring constant
U
spring
1
2
---kx
2
=
Potential energy stored in
a spring
U
gravity
mg
s 
sin =
Potential energy of a cart
on an inclined track