An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^(-1) and the second part of mass 2 kg moves with 8 ms^(-1) speed. If the third part flies off with 4 ms^(-1) speed, then its mass is

An explosion breaks a rock into three parts in a horizontal plane. Two

1.	An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^(-1) and the second part of mass 2 kg moves with 8 ms^(-1) speed. If the third part flies off with 4 ms^(-1) speed, then its mass is
Answer» 7kg 17kg 3 KG 5KG Solution :Thesituationis asshownin thefigureaccordingto lawofconservationoflinearmomemtum ` vecp_1 + vecp_2 + vecP_3=0 thereforevecP_3 =-vecP_1 + vecP_(2)` here` vecv_1= ( 1 kg) ( 12 ms^(-1)) HATI= 12 hati kgms^(-)` ` thereforevecP_3 = - (12hati+ 16hatj ) kg ms^(-1) ` Themagnitudeof `P_3` is ` P_3 = sqrt((12)^2 + (16)^2) = 20kg ms^(-1)` ` thereforem_3 = (p_3)/(v_3) =( 20 kg ms^(-1))/(4 ms^(-1)) =5kg `