Please what is the work done by a man who is pulling a box of 45kg of mass by means of rope which makes angle of 45 degrees ?

No work is done since no distance is given

Explanation:

Since no distance is given, the force is not doing any work

No work is done by the man since we do not know the distance or displacement.

Work is only said to be done when the force applied on an object moves it through a particular distance.

Work done  = Force x distance.

Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.

d) physical means can be used to separate the components of air.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.