The weight of a body kept at a distance of 6400 km from the centre of the earth is 10N. What will be the weight of another object kept at a distance of 12,800km ?

2.5N

Explanation:

since force is inversely proportional to square of the distance apart. that means the ratio of distance apart. so u have 12800×12800÷(6400××6400)=4/1

so the weight will be reduced to 1/4 of 10N

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