00:01
So let us start with the concept which we are going to use here for this question.
00:07
So since we know that mechanical energy is nothing but the total energy of the system which is the combination of potential energy plus the kinetic energy.
00:17
So according to the question the mass of the child is of m is equals to 250 kg.
00:22
We're sliding down from the hill into downward direction.
00:27
Frictionless hill.
00:30
Now height of the hill is nothing but given to us let's say h is equals to 7 .34 of meters.
00:39
So it is starting from rest that means initial speed is 0 meter per second.
00:45
So we have to find the mechanical energy of the system and the slidy speed at the bottom of this hill.
00:52
So let us start with this.
00:54
So first of all the mechanical energy of the system will be equals to the potential energy plus kinetic energy.
01:01
So let's say this mechanical energy would be equals to no potential energy will be simply mgh plus kinetic energy will be one half mv square.
01:12
Okay so let's substitute all the required values.
01:15
So this will be equals to so mass is 50 multiplied by value of g is known to us 9 .8 meter per second square multiplied by height is 7 .34 plus one half mass is 50 multiplied by.
01:29
Now initially it is starting from rest that's why the speed or velocity will say will be equals to zero.
01:36
So this whole term will be going to be equals to zero...