00:01
We have been given that there is an object and this object has a mass of 3kg and it's initially at rest and this explodes into three other fragments which have equal mass and of course these three fragments will be having mass of one kilograms each and we have been given that one of the mass is moving along the east direction with a speed of 15 meter per second and there is another mass which moves with a speed of 10 meter per second at an angle of 45 degree south of east.
00:38
So let's indicate here the right direction as the east direction, the bottom as the south, top as the north, and the left as the west direction.
00:48
And the second mass is moving at an angle of 45 degree south of east.
00:54
So basically it will be moving along this direction and this will be 45 degree.
01:01
And the speed with which it moves is 10 meter per second.
01:05
So its velocity will have two components, one along the east direction and the other along the negative south direction basically here.
01:13
So its velocity vector will be 10 costs 45 degree along minus j cap, which represents the direction along the south.
01:23
Plus 10 sine 45 degree along the positive x -axis, which is along the east direction here.
01:31
So from here, when we simplify, we're going to get the velocity vector as 5 root 2 i -cap minus 5 root 2 j -cap.
01:41
And we have to determine the magnitude as well as the direction of the velocity of the third mass.
01:48
So as we can observe here, there is no external force which is acting here.
01:52
So the momentum will be valid and total initial momentum is zero because the particle of mass 3kg that was initially addressed.
02:02
And that's equal to the total final momentum, which will be equal to the momentum of this first mass.
02:08
So that will be mass times its velocity and that will be 15 icap plus the momentum of the second mass, which will be its mass times the velocity vector, which is 5 root 2 icap.
02:22
Minus 5 root 2 jcap.
02:25
And to this we add the momentum of the third particle, which is its mass times the velocity vector...