An object consists of a rod (of length 4.0 m and negligible moment of inertia) to which five small 1.0-kg massesare attached, one at each end and one at each point on the rod 1.0 m from each end. (the masses are one meterapart.) the moment of inertia of this object about an axis perpendicular to the rod and through one of the endmasses

I = 30 kg m²

Explanation:

given,

length of rod = 4 m

mass of the 5 small masses = 1 kg

masses are kept at an interval of 1 m

Moment of inertia of the object = ? from the end mass

now distance of the masses from the end

r₁ = 1 m    r₂ = 2 m   r₃ = 3 m  r₄ = 4 m

hence, the moment of inertia

I = I₁ + I₂ + I₃ + I₄ + I₅

I = mr₁²+ mr₂² + mr₃² + mr₄² + mr₅²

I = 1 x 0²+ 1 x 1² + 1 x 2²+ 1 x 3² + 1 x 4²

I = 1  + 4+ 9 + 16

I = 30 kg m²

hence, the moment of inertia of the object is I = 30 kg m²

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.