1.
Displacement-time equations of two particles moving along the xx-axis are x1=8+3sin(ωt)x_1 = 8 + 3\sin(\omega t) and x2=4cos(ωt)x_2 = 4\cos(\omega t), where ω=πrad/s\omega = \pi\,\text{rad/s}. The two particles will collide after a time