Homework Help: physics

Posted by susan on Tuesday, February 13, 2007 at 12:19am.

Two sinusoidal waves travel in the same direction and have the same frequency. Their amplitudes are Y1 and Y2. The smallest possible amplitude of the resultant wave is:
a) Y1 + Y2 and occurs if they are 180 degrees out of phase
b)[Y1 - Y2] and occurs if the are 180 degrees out of phase
c) Y1 + Y2 and occurs if they are in phase
d) [y1-Y2] and occurs if they are in phase
e) [Y1-Y2] and occurs if they are 90 out of phase

My thoughts:
All the explainations of resultants in my book for waves show Y1+Y2=Resultant for the theory of superposition. So I think then to get the smallest wave it would be A. Y1 + Y2 if they are 180 degrees out of phase.

The displacement of a string is given by
y(x,t)=Ysin(Kx + wt)
speed of the wave is
a)2pik/w
b)w/K
c)wk
d)2pi/k
e)k/2pi

Work:
v=lamba*f
k=2pi/lambda
w=2pi/T
v=2pi/lambda * 2pi/(1/f)
v=w/k
so I choose b

Help is appreciated :)

No one has answered this question yet.

Answer this Question

Related Questions

Physics (please help) - Two sinusoidal waves travel in the same direction and ...
Physics waves - Two sinusoidal waves travel in the same direction and have the ...
physics - Two sinusoidal waves of the same frequency travel in the same ...
physics - Two sinusoidal waves of the same frequency travel in the same ...
physic - The waves emitted from a source A is given by y1 = 6 sin π(20t...
physics (please help) - Two identical but separate strings, with the same ...
physics - waves - Two sinusoidal waves, identical except for phase, travel in ...
physics - Two waves are travelling on a string in the same direction. Both have ...
Physics - Which one of the following will form a standing wave: (1) two waves of...
physics - Which of the following conditions is not necessary to observe an ...

For Further Reading

First Name:
School Subject:
Answer: