the area of 1 end of U-tube is 0.0 metre square and that of the other end is 1 metre square when you force was applied on the liquid at the first in the force experienced at the other end was 20000 N what was the force explain applied on the first end

The question is wrong Since if you apply Force on 0.0m²It would mean That the pressure exerted=F/A=F/0

An since we can't divide a number by 0, the question is wrong

frequency or wavelenth of em radiation in a vacuum

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards