00:01
Hello, here we have to solve the following problem.
00:03
Block m is pushed with a force p up the incline and there is a friction force in between the incline and the block.
00:13
Let's quickly sketch it.
00:20
Incline makes an angle theta and now let's show the forces which are acting on the block.
00:28
The gravity is downwards, normal reaction is perpendicular, force p is up the end.
00:39
Incline and friction is against the motion and now we have to calculate the work done by each force let's start with one in question one we have to provide the work done by the hand so we have to find the work done by p so this work equals to p times the displacement d and d is simply up the incline so therefore this is because that is p times d times cosine of zero degree and that's a positive number.
01:23
Now let's move on to the next one.
01:31
Now we have to determine the work done by the normal force and that is normal force times d times cosine of 90 degree which is 0 joules.
01:43
So now let's actually match the answers.
01:48
So to the one, to question one we have to choose c to question d.
01:53
We have to choose a...