AP EAMCET Medical 23 Apr 2019 Shift 2 Paper

Three particles A, B and C simultaneously start from the origin. Particle A moves with a velocity V along X-axis, particle B moves with a velocity TV along Y-axis and particle C moves with a velocity ‘c’ in the X-Y plane along the straight line x = y. The magnitude of ‘c’ so that all the three particles always remain col linear is