00:01
Everyone so in a given numerical a block of mass am slide down with a rough inclined plane okay so we are consider this is the inclined plane okay and that make a angle of a theta if a anybody okay that is having a mass am and it will be moving in that direction with a this is the rough surface guys okay that is a rough surface and the friction coefficient of a plane is given a mu okay with a theta is also given with a theta is gravity than of a 10 inverse of a mu guys, okay, rate of work done by the force of friction.
00:36
So first of all we are consider that initial velocity, the initial velocity of that particle is equivalent to a 0.
00:47
Now this is the according to that diagram if you are considered that value, so this is the direction of a mg and this is the direction of mg sine theta.
01:00
The friction force will be applied in an opposite direction that is a mu m g cost theta okay because this as m g cost theta and this m g cost theta is balanced by that a normal force okay so we use that frictional force okay okay so if you are consider f net so f net is equivalent to a m g sine theta mg sine theta minus of a mu m g cost theta okay now f net is equivalent to m into a is equivalent to m into g sine theta minus of a mu and g cost theta okay the m will be cancelled in a whole data so m will be cancelled so we get the acceleration a is equivalent to a g sine teta g sine teta and minus of a mu into g cost theta this is the acceleration which is play a role in that plane okay so to calculate a bit because of we know that the work done per unit time that is called a time that is called a power so we calculate the rate of work done is also called a power rate of work done students okay now so for in that equation we can calculate a power in the form of a force multiplied by a velocity so what is the velocity guys so velocity v is equivalent to u plus a into t you becomes a zero so so a, we know that, that is above equation g sine theta, minus of a mu into g cost theta, and the time period is a t multiply.
02:40
Okay? so now we put up that values and we get your answer, power is equivalent to a force is a mu mg, cost theta, and multiply.
02:52
That is a force, which force? that is a frictional force...