PASCO ME-9215B Photogate Timer - Manual (Page 26)

22
Photogate Timer 012-06379B
®
j
Repeat steps 5-8 four more times. Record your times as t
2
through t
5
in Table 9.2. Determine
the average of these five times and record this value as t
avg
.
k
Repeat steps 5-9 for different distances of stretch of the spring up to 20 cm. Also try varying
the mass of the glider by adding masses to it. Note the new masses in Table 9.2.
Data and Calculations
On another sheet of paper:
c
Determine k, the spring constant of your spring. Construct a graph of the stretch of the spring
versus the amount of force applied to it by the hanging weights. The slope of this graph, in
newtons/meter, is equal to k.
d
For each set of trials you performed for a given spring stretch and glider mass, divide
Δd by
your average time to determine the average velocity of the glider as it passed through the
photogate. Calculate the final kinetic
energy of the glider, 1/2 mv
2 .
e
Calculate the energy stored in the spring
in each case, 1/2 kx
2
, where k is the
spring constant, and x is the spring
stretch.
f
For each trial, determine the percentage
difference between the elastic potential
energy stored in the spring and the final
translational kinetic energy of the glider.
Trial m
Spring
Stretch
t
1
t
2
t
3
t
4
t
5
t
avg
x
1
= Flag width, Δ Δ Δ Δ Δd
=
Table 9.2 Spring Stretch and Glider Velocities
Added Glider Applied Spring
Mass Position Force Stretch
Table 9.1 Determining the Spring Constant