In a pairs skating competition, a \(75-\mathrm{kg}\) male skater moving at \(4.0 \mathrm{~m} / \mathrm{s}\) collides (gently) with his stationary, \(50-\mathrm{kg}\) female partner and raises her in a lift. Neither of them makes a horizontal push at the instant of the pickup. What is the speed of the pair after the collision? (The vertical motion of the female has no bearing on the question.)