A 5kg block is pushed 3m at a constant velocity up a vertical wall by a constant force applied at an angle of 37 degree with the horizontal, if the coefficient of kinetic friction between the block and the wall is 0.3. what is the work done by the force on the block?

The work done by the force on the block is:

The direction of motion here is in the y-direction, so we need to find the component of the force in this direction.

Using trigonometric functions:

This component is in the positive y-direction.

Now, there is a friction force between the block and the wall, so we need to find the friction force.

Where:

μ is the coefficient of kinetic frictionN is the normal force (Here N = Fcos(37))

Let's use the first Newton's Law to get F.

F(y) is upward (+) and F(f) and the weight is downward (-).

Factoring F in the left side:

   

 

 

   

Therefore, the work done will be:

 

 

You can learn more about work definition here:

         

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.