[填空题]
Four 1.0-kg masses are located at the corners of a square 0.50 m on each so*2zit mkpndm cm z:t* 2ir34xrnb4uw.rw73 0ide. F.* 4 zn0pw*2dc4ri2t7wt on:mmku3ri3z rm bx 4sazkaix,w31 f gzs6,ind the magnitude and direction of the gravitational force on a ,,wi36 ksaz 1gx sf4azfifth 1.0-kg mass placed at the midpoint of the bottom side of the square. $\times 10^{-10}$
