Wave motion and two detectors to measure that motion

[tina21]

Homework Statement

Envision a wave of the form y(x,y)=100sin(2*pi*x - 4*pi*t) and locate two detectors to measure the disturbances at points x1 = 2 and x2 = 10. What will be the magnitude of the disturbance at the instant t' when y(x1, t') = 100.

Relevant Equations

y(x,y)=100sin(2*pi*x - 4*pi*t)

Solving for t' by substitution I obtained t' = 7/8. Then I substituted x= 10 and t = 7/8 in the given equation. Is that the right way to do it? My answer key says the answer is 100 but I am getting 78.5.

 

[haruspex]

Homework Statement: Envision a wave of the form y(x,y)=100sin(2*pi*x - 4*pi*t) and locate two detectors to measure the disturbances at points x1 = 2 and x2 = 10. What will be the magnitude of the disturbance at the instant t' when y(x1, t') = 100.
Homework Equations: y(x,y)=100sin(2*pi*x - 4*pi*t)

Solving for t' by substitution I obtained t' = 7/8. Then I substituted x= 10 and t = 7/8 in the given equation. Is that the right way to do it? My answer key says the answer is 100 but I am getting 78.5.

I get 100. Please post the rest of your working.
(The quick way is to consider what happens to 2πx as x changes from 2 to 10.)

 

[tina21]

I get 100. Please post the rest of your working.
(The quick way is to consider what happens to 2πx as x changes from 2 to 10.)

Hey... I finally got 100 too. Thanks for the help, I looked more carefully and found the error in the calculations