Which option below correctly compares the amount of radiation exposure from an annual dental X-ray and the radiation exposure from background radiation during the same year?

A. The dose from the dental X-ray is 8000 times smaller than the
average annual dose of background radiation.
B. The dose from the dental X-ray is 8000 times larger than the
average annual dose of background radiation.
C. The dose from the dental X-ray is 20 times larger than the average
annual dose of background radiation.
D. The dose from the dental X-ray is 20 times smaller than the
average annual dose of background radiation.

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.