Help Needed! Waves, Urgent!!!

[saksham]

******Mathematical description of a wave:******

A transverse wave on a string can be described by:
Y(x,t)= A cos [k(x-vt)]

a) Find the maximum transverse speed vy of a particle of the string. Under that circumstances is it equal to the propagation speed of the wave?

b) The wave has an amplitude of 0.300 cm, wavelength 12.0 cm, and speed 6.00 cm/s. What is its frequency? What is the deflection of a particle of the string at time t = 5 s and position x = 10 cm?

Please help me out! I have deadline tonight.
Best,
Physicist.

[Doc Al]

Hint for a: Find the transverse speed by taking the derivative.

Hint for b: Use the wave equation: v = f \lambda.

Hint for both: Crack open that textbook! :smile:

[saksham]

Under what circumstances are the traverse speed and speed of propagation equal?