3) A rod AB carries three loads of 30 N, 70 N and 100 N at distances of 20 mm, 90 mm and 150 mm respectively from A. Neglecting the weight of the rod, the point at which the rod will balance is

4) The angles between two forces to make their resultant a minimum and a maximum respectively are

5) When two forces, each equal to P, act at 90° to each other, then the resultant will be

6) The resultant of two forces P and Q is R. If Q is doubled, the new resultant is perpendicular to P. Then,

7) A cube on a smooth horizontal surface