Recent postsView all

Money
14 Feb 19
Gp4 hands off / hands on
10 Feb 19
Wolf blood moon
22 Jan 19
New lab :-)
11 Jan 19
Happy New Year! (EM)
3 Jan 19
Google classroom idea
2 Jan 19
Making connections
21 Nov 18
Cross and dot
31 Oct 18
The wow factor
23 Oct 18
Causing tension
13 Oct 18
Physics gender gap (EM)
13 Oct 18
How many zlings in your plodge?
29 Sep 18

Wasps

Thursday 19 July 2018

Lots of wasps around at this time of year, you can tell them by the way they buzz, not as frantic as a bluebottle, but more so than a bee. Have you noticed how the frequency of the buzz goes up and down as they fly around the room, I wonder if it's due to the doppler effect or the frequency of the wings. Let's assume the wing frequency is constant and use the doppler shift to find the speed of a wasp. I found a recording of a wasp on youtube and used audacity to measure the frequency of the lowest and highest sound.

highest 141 Hz

Lowest 133 Hz

So the wing speed at rest is likely to be the average  137 Hz

The highest note is when the wasp approaches so f' = fc/(c-v)

Rearranging gives v = 9.7 ms-1 about 35 km/h. According to google the Asian hornet can fly at 40 km/h and a wasp is something like a hornet so it does seem possible that the change in frequency is indeed due to the doppler effect.


Holidays
2 Jul 2018

Comments


To post comments you need to log in. If it is your first time you will need to subscribe.