00:01
The given problem, the track between a to b is frictionless, has no has no miss friction.
00:12
It means there is no loss of energy between a to b.
00:18
It means kinetic energy at point b where it just starts to travel on the rough surface should be equal to potential energy at point a.
00:34
Because at point a, the kinetic energy is zero because it has not started to move.
00:39
So it has got only potential energy.
00:42
Similarly, at point b, the height is zero.
00:45
So potential energy is zero.
00:47
So it has got only kinetic energy.
00:50
So what is the potential energy at a is equal to m g h.
00:56
Now, m is the mass 15 kg, g is 9 .8, and h is the height.
01:03
Height is 3 meter this all data is given in the problem so this comes out to be 4 41 june this is the kinetic energy at b right and now after the block passes through the rough part of 6 meter length it travels some portion on the frictionless surface and then it hits the spring so let and then it hits the spring and compresses the spring so it means the kinetic energy at point c kinetic energy at point c is something which is finally used to compress the spring and this if it finally converts into the spring potential energy because when spring is compressed it is it is converted into a spring potential energy means 1 half kx square.
02:11
So now we have all the values, the value spring constant is 2 .150 newton per meter and the spring is compressed by 43 cm, means 0 .43 meter.
02:24
So this comes out to be 198 .8 jule...