The answer of this is C!!!
><span>It can travel through vacuum.
The rays must travel in the vacuum of space between Earth's atmosphere and the sun.</span>
B. Ptolemy believed that the earth was the center of the universe
I think the question meant to say net force on the box. Since force is a vector, the direction matters. 20N left is negated completely by the 50N right, which means the net force is 50N-20N to the right, 30N.
