A wrench 30cm long lies along the positive y-axis and grips a bolt in the origin. A force is applied in the direction < 0; 3; -4 > at the end of the wrench. Find the magnitude of the force needed to supply 100J of torque to the bolt. how can i solve it? r=<0,.3,0> F=<0,3,4> T= r X F =100 then i solved it by finding the det = 100 |i j k| |0 .3 0| = 100 |0 3x -4x| then x = 83.333 N but the answer is wrong Why???