00:01
Hello friends, in this question it is given that there is an ice hockey player and mass of this ice hockey player is 90 .5 kilograms and there is a puck of mass 0 .17 kilogram.
00:19
So initially both of these were at rest.
00:23
But when this hockey player hits this puck, this puck travels or it starts.
00:30
With a speed of, let us assume the speed of this is v2f, it is equal to 48 .5 meter per second.
00:42
So in this case we are given that after the collision between these two, so the puck travels a distance of 14 meter away to reach to the goal.
00:57
So in this in the same time required for this perk to reach the goal which is of the 14 meter distance, what will be the distance d .h covered by the hockey player in the with the recoil velocity in the opposite direction.
01:19
So for this we will use initially law of conservation of momentum, linear momentum.
01:26
So according to law of conservation of linear momentum, the initial momentum of the puck and that hockey player is equal to the final momentum of both of these.
01:37
Initially both of them were at rest.
01:40
So initial momentum is zero and the final momentum will be m1 v1f plus m2v2f.
01:50
Now we know that the value of v2f is 48 .5 minutes.
01:56
Per second but we can calculate the recoil velocity of that hockey player after the collision with the help of this formula so 0 will be equal to 90 .5 multiplied by v1f plus 0 .17 multiplied by 48 .5 so we can write v1 f is equal to minus of 0 .17 multiplied by 48 .5 and divided by 90 .5.
02:29
We will calculate this now...