An opaque box encloses a region of space. we can't tell what is inside the box but we can see that on all faces of the box there is a non-zero electric field pointing inward. what can we conclude about the charge enclosed within the box?

The charge must be negative

Explanation:

Hi!

The direction of the electric field of a charge depends on the sign of the charge, when it is positive, the electric field points outwards the charge but when it is negative, it points towards the charge. (As you can seen on teh attached image)

So, if on the faces of the box, the non-zero elecric field points inwards, it must mean that the total charge inside the box must be negative

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but hope this

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