The velocity of the particle is given by

Since
and
, we get


Similarly, the position function is obtained via

We know
and we're told that
, so


making the answer A.
Answer:
B. c = fλ
Step-by-step explanation:
The given equation is

To solve for c you must multiply both sides of the equation by lambda.

Don't know if it's right, but do let me know! use percentage to visualise your workings. :)
$ 1.85 you divide 22.20 by 12