A \(2.0-\mathrm{kg}\) cart and an \(8.0-\mathrm{kg}\) cart are connected by a relaxed, horizontal spring of spring constant \(300 \mathrm{~N} / \mathrm{m}\). You pull the \(8.0-\mathrm{kg}\) cart with some constant horizontal force. The separation between the carts increases for a short time interval, then remains constant as you continue to pull and the spring is stretched by \(0.100 \mathrm{~m}\).

(a) What pulling force did you exert?

(b) If you instead pull the \(2.0-\mathrm{kg}\) cart, what force must you exert to get the same stretch in the spring?