Why is the horizontal velocity of a
projectile constant?

Explanation:

I'll try to answer this is clearly as possible without talking in circles. If an object is launched into projectile motion, something was behind it, pushing it forward. Once this launching was done, the launching mechanism was no longer important to the object and the object is free to keep moving forward at that same velocity forever...if that was the only thing at play here. But, because of air resistance and GRAVITY, the object is pulled down and eventually hits the ground. In other words, if there was no such thing as gravity, an object would continue to move forever in the diretion and at the speed at which it was launched.

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

the rearrangement of particles in a physical change. hope this