Question

if you are trying to push a heavy box on a horizontal surface list various forces acting on the box. state the condition under which this box will start siding on the surface. how will the magnitude of applied force required to move the box change it .1) weight of the box is increased. 2) the surface on which the box is played is made more rough

Answer 1

The various forces that act on it are,

Normal force,

Weight,

External force applied by us,

friction and some minor if we think more accurately !

Answer 2

When h are sliding a box, frictional force,gravitation force and the muscular force u are applying can be seen.The box will start sliding when your force is more than the frictional and other forces.
If the weight of the object increases,then the frictional force increases.So,you will have to apply more force.
If the surface u are dragging ur box becomes even more rough,frictional force increases and so u will have to add more force to move the box.

Less friction=less force
More friction=more force