[填空题]
A 70-g bullet travelin ( dipv1m3aoegycd/y13 b*yaka 2rgzan)/ d;*g aiapw/, g/ h9 15 (;q5p 9rgdslroooevst $250\,m/s$ penetrates a block of ice at 0$^{\circ} C$ and comes to rest within the ice. Assuming that the temperature of the bullet doesn’t change appreciably, how much ice is melted as a result of the collision? g