What is required for an electromagnet to produce a magnetic field that is strong enough to be useful?
A. A coil of wire with current running through it
B. A magnetic metal core with wire wrapped around it
C. A permanent magnet
D. A magnetic metal core
SUBMIT

The scalar triple product computes the magnitude m of the moment of a force vector f about a specified line. it is m = (r × f) · n, where r is the position vector from the line to the point of application of the force and n is a unit vector in the direction of the line. use matlab to compute the magnitude m for the case where f = [12, −5, 4] n, r = [−3, 5, 2] m, and n = [6, 5, −7].