to be franc i really think the answer is B
The equation for work (W) done by an electric field is:
W = qΔV
where q is the magnitude of the charge and ΔV is the potential difference. The question gives you W and q, so plug n' play to find ΔV:
10 = 2ΔV
ΔV = 5
V = 340 m/s
f = 256 Hz
lambda (wavelength)
v = f*lambda
340 = 256 * lambda
340/256 = lambda
lambda = 1.328 m
The tangent looks good.
The curve is a bit crooked, at the 0.9 and 1.
But overall, cool graph.
Earths atmosphere heats up polars melt
