Scientists design a new particle accelerator in which protons (mass 1.7 times 10⁻²⁷ kg) follow a circular trajectory given by r = c cos (kt²)i + c sin (kt²) j, where c = 1.0 m and k= 8.0 times 10⁴ rad/s² are constants and t is the elapsed time. What is the radius of the circle?
