 # At the initial moment three points A,B and C are on a horizontal straight line at equal distances from one another. Point A begins to move vertically upward with a constant velocity "v" and point C vertically downward without any initial velocity at a constant acceleration "a".How should point B move vertically for all the three points to constantly be on one straight line? The points begin to move simultaneously.please help me out quick.

11 years ago

Sorry bro but I think the distance between the points is required because the answer depends on it.

HINT

Take B on the origin and A at (-d,0) and C at (d,0) now position of A after time t is (-d,vt) and that of C is (d,at2/2) now from these points write eqn of line in two point form and put x = 0 to obtain a relation between y co ordinate of B and the rest of parameters.

• Simplify the eqn and compare to the standard eqn for distance s = ut + at2 /2 to obtain the initial velocity and accn.

NOTE : The solution is in general for the point except the bullet because in that point the acceleration has been assumed to be constant otherwise problem becomes too complex.

11 years ago 