When three coplanar and non-parallel forces are in equilibrium,
I. they can be represented in magnitude and direction by the three sides of a triangle taken in order.
II. their lines of action meet at a point.
III. the magnitude of anyone equals the magnitude of the resultant of the other two.
IV. any one force is the equilibrant of the other two.
Which of the following statements above are correct?
A ball of mass 0.5kg moving at 10ms-1 collides with another ball of equal mass at rest. If the two balls move off together after the impact, calculate their common velocity.
