a 500v should motor runs it's normal speed of 250rpm when armature current is 200A. the resistance of armature is 0.18ohm. calculate the speed when resistance is inserted the in the field reducing the shunt is 80% of normal value and the armature current is 100A​

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft