1. The problem statement, all variables and given/known data Hello all, stuck on a question involving a formula for a wave that doesn't make much sense to me. Assuming that a wave on a string is represented by: y(x,t) = y_i*sin((2∏/λ)(vt-x)) Where y is transverse displacement at time t of the piece of string at x. The other symbols have their "usual meaning". Find the velocity and acceleration of the small piece of string at x = 10m, as a function of time. Making use of the fact that the piece of string satisfies Newton's second law, show that the piece of string is acted on by a Hooke's Law force. 2. Relevant equations y(x,t) = y_i*sin((2∏/λ)(vt-x)) y(x,t) = A*sin(kx - ωt) k = 2∏/λ 3. The attempt at a solution I'm a bit confused by the format of the formula... I know that to find velocity and acceleration, I can take the derivative of the equation once for velocity and again for acceleration. Looking at the set up, it looks like if we replace 2∏/λ with k and expand, we see in the brackets (kvt - kx) where kv could equal ω? I don't know if this is at all valid. I also don't understand why the variable "v" is used in the equation, but from the question i can assume that it is analogous to omega ω. So y(10,t) = y_i*sin((2∏/λ)(vt-10)) v(10,t) = y_i*cos((2∏/λ)(vt-10))*??? I'm having trouble knowing how to take the derivative of this when I don't know λ and v. Unless they are constants and I can ignore them? Any help will be appreciated... Thanks.