Solve this:
15. A particle moves through the origin of an xy-cordinate system at t=0 with initial velocity u=4i-5j m/s. The particle moves in the xy plane with an acceleration a=2i m/s2. Speed of the particle at t=4 second is:
(1) 12 m/s (2) m/s (3) 5 m/s (4) 13 m/s
(1) 12 m/s (2) m/s (3) 5 m/s (4) 13 m/s