For the harmonic travelling wave, y=2cos2π10t-0.008x+3.5 where x and y are in cm and t is in second. What is the phase difference between the oscillatory motion at two points separated by a distance of:

1. 4m

2. 0.5m

3. λ2

4. 3λ4 (at a given instant of time)

5. What is the phase difference between the oscillation of a particle located at x=100cm, at t = T sec and t=5 sec?