Transverse and Longitudinal Waves in a Slinky Spring
By: Farheen Ahmad
Purpose: To determine what changes occur as a transverse or a longitudinal wave travels along a slinky spring.
• Masking tape
• Meter skip
• Stop watch
• 5 meter long slinky
a) Place the slinky spring horizontally on a hard, smooth floor.
b) Attach small pieces of masking tape to the spring approximately ¼ of the distance in from each end and at the middle point of the spring.
c) Place two pieces of tape on the floor and slightly in from the ends of the spring. These will be the speed markers.
d) Measure the distance between the speed markers.
e) While student A holds one end of the spring firmly in place. Student B stretches the spring from the other end so that it is moderately taut.
f) Student B then creates a transverse wave by flicking the end of the spring a small distance sideways and quickly back again. Record observations.
g) Repeat the timing for two more runs.
h) Determine the average time and calculate the average speed of the wave.
i) Keeping the spring stretched the same amount, send another transverse wave with a larger amplitude down the spring. Determine its speed as before.
j) Repeat (i) for amplitude smaller than the original.
k) Slowly flick the spring out and back to send a lower frequency wave along the spring. Determine its speed as before.
l) Repeat (k) with a higher frequency wave. Try to keep the amplitude the same as in (k).
m) Compress about ten coils at the end of the spring while keeping the tension in the rest of the spring the same as in (l). Release the coils and record observations.
n) Calculate the speed of this wave.