How many seconds after the force is applied does the bar reach a speed of 21.6m/s?Express your answer with appropriate units.

A conducting rod with length 0.187 m , mass 0.140 kg , and resistance 80.7 0 moves without friction on metal rails as shown in the following 1igure(E-'_igg_rit_). A uniform magnetic field with magnitude 1.50 T is directed into the plane of the figure. The rod is initially at rest, and then a constant force with magnitude 1.90 N and directed to the right is applied to the bar. Figure 1 of 1