Find moments Mx and My and the center of mass in: m1 = 6 ; P1 = (1,5)
m2 = 5 ; P2 = (3,-2)
m3 = 10 ; P3 = (-2,-1)

Abox is pushed down at an angle of 32 degrees on a rough surface. the box moves to the right.what equation should be used to find the net force in the y-direction? answers: a. fnet,y = fn - fgb. fnet,y= fp - ffc. fnet,y = fn-fg- fpcos(32)d. fnet,y = fn-fg-fpsin(32)

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?