Erica ( \(36 \mathrm{~kg}\) ) and Danny ( \(47 \mathrm{~kg})\) are bouncing on a trampoline. Just as Erica reaches the high point of her bounce, Danny is moving upward past her at \(4.1 \mathrm{~m} / \mathrm{s}\). At that instant he grabs hold of her. What is their speed just after he grabs her?