Answer:
The distance between two posts
Explanation:
As the students have already measured the amount of time necessary for the wave to oscillate up and down that is on the string between two posts,They have to measure the speed of the wave.
ie v=fλ
<em>They have to measure distance between the posts.
</em>
Because wavelength is equal to the distance between the posts ie full length of string.
The frequency of the wave is calculated by
f=
1/T
Where is the time period which the students have calculated ie the amount of time taken to oscillate up and down,
Thus the wave speed is calculated using formula
v=λ/T
Benjamin Banneker Published his almanac based on his astronomical calculations in 1792. Hope this helps:)
