Two Rb-87 condensates (F = 2, m(f) = 2, and m(f) = 1) are produced in highl
y displaced harmonic traps and the collective dynamical behavior is investi
gated. The mutual interaction between the two condensates is evidenced in t
he center-of-mass oscillations as a frequency shift of 6.4(3)%. Calculation
s based on a mean-field theory well describe the observed effects of period
ical collisions both on the center-of-mass motion and on the shape oscillat
ions.