Problem 18P

Calculate (a) the tension FT in the wire that supports the 27-kg beam shown in Fig. 9–52, and (b) the force exerted by the wall on the beam (give magnitude and direction).

FIGURE 9–52

Step 1 of 3The total momentum of system after collision is equal to the total momentumbefore collision. The momentum is quantity of measurement of motion of object. Mathematically, p=mv In an isolated system , the total momentum is conserved because there is no external force acting on it . Consider two bodies Initial momentum of the bodies before collision p and p 1espectiv2ly final momentum of the bodies after collision p and p1respectiv2ly From newton's second law F= dp dt Force exerted on 1 by 2 ,F = p1 1p 12 t Force exerted on 2 by 1 ,F = p2 2p 21 t By newton's third law F 12 =-F 21 p11 (2 2p ) t = t p1- p 1 (p -2p ) 2 p1- p 1p +2p 2 p1- p2=p 1 p 2 This is law of conservation of momentum