Q 15

A transverse wave is traveling on a string stretched along the horizontal x-axis.The equation for the vertical displacement y of the string is given by y = 0.0020 cos[π(15x - 52t)],where all quantities are in
SI units.The maximum speed of a particle of the string is closest to
A) 0.33 m/s.
B) 0.43 m/s.
C) 0.53 m/s.
D) 0.64 m/s.
E) 0.74 m/s.

Q 16

Find the speed of an ocean wave whose vertical displacement y as a function of time t is given by
Y(x,t)= 3.7 cos(2.2x - 5.6t),where all quantities are in SI units.
A) 2.5 m/s
B) 1.9 m/s
C) 3.5 m/s
D) 4.5 m/s

Q 17

You and your surfing buddy are waiting to catch a wave a few hundred meters off the beach. The waves are conveniently sinusoidal,and you notice that when you're on the top of one wave and moving toward your friend,she is exactly halfway between you and the trough of the wave. 1.50 seconds later,your friend is at the top of the wave.You estimate the horizontal distance between you and your friend at 8.00 m.
(a)What is the frequency of the waves?
(b)Find the speed of the waves.