Two carts, A and B, are connected by a rope 39 ft long that passes over a pulley \( P \). The point \( Q \) is on the floor 12 ft directly beneath \( P \) and between the carts. Cart \( A \) is being pulled away from \( Q \) at a speed of \(3\mathrm{ft}/\mathrm{s}\). How fast (in \(\mathrm{ft}/\mathrm{s}\)) is cart \( B \) moving toward \( Q \) at the instant when cart \( A \) is 5 ft from \( Q \)?(Round your answer to two decimal places.) ft/s