Two particles released from the same height and reached the base at the same time

Problem
Particles A and B are elevated 12 meters high from a given reference base. Particle A is projected down an incline of length 20 meters at the same time particle B is let to freely fall vertically. Find the velocity of projection of particle A if both particles strikes the base at the same time.
 

001-two-particles-released-thesame-point.gif

 

Support Reactions of a Trapezoidal Slab with Three Points of Support

Situation
A reinforced concrete slab in the shape of an isosceles trapezoid weighs 3600 N/m2. It is supported on the three points as shown in the figure.
 

eq-parallel-forces-trapezoid-slab.gif
  1. Find the reaction at A.
    A.   16,848 N
    B.   6,716 N
    C.   13,372 N
    D.   2,010 N
  2. Find the reaction at B.
    A.   16,848 N
    B.   6,716 N
    C.   13,372 N
    D.   2,010 N
  3. Find the reaction at C.
    A.   16,848 N
    B.   6,716 N
    C.   13,372 N
    D.   2,010 N

 

Equation of the Locus of a Moving Point

Definition of a Locus
Locus is a Latin word which means "place". In mathematics, locus is the set of points that satisfies the same geometrical properties. In most cases, the relationship of these points is defined according to their position in rectangular coordinates.
 

Example 1
Determine the equation of the curve such that the sum of the distances of any point of the curve from two points whose coordinates are (-3, 0) and (3, 0) is always equal to 8.
    A.   4x2 + 49y2 - 343 = 0
    B.   7x2 + 16y2 - 112 = 0
    C.   7x2 - 16y2 + 112 = 0
    D.   4x2 - 49y2 + 343 = 0