Two 2. 4-kg blocks are connected by a string draped over the edge of a slippery table, so that one block is on the table and the other is just hanging off the edge. A restraint holds the block on the table in place, and the string is \(0.50 \mathrm{~m}\) long. After the restraint is removed, what speed does the pair of blocks have at the instant the upper one is pulled off the table?