41. During a game of billiards, the 0.30-kg cue ball, travelling at 2.1 m/s, glances off a stationary 0.28-kg
billiard ball so that the billiard ball moves off at 1.4 m/s at an angle of 38° from the cue ball's original path.
Find the new speed of the cue ball.(3)
42. Calculate the electric potential a distance 0.56 m from a point charge of -3.6 × 10<sup>4</sup> C.(3)