b) For the next one second, i.e., 2-3 second period, the quadcopter is put into a roll motion by increasing the velocity of the fourth rotor and decreasing the velocity of the second rotor. In the next one second, the roll rate is made zero by the increasing the velocity of the second rotor and decreasing the velocity of the fourth rotor. N = 2 N = 2 hover hover 70 sin(2(t 2)/4), N = N +70 sin(2(t 2)/4), N = N - hover + 70 sin(2(t 2)/4), 2