Rate of distance travelled is speed.
Speed = distance/time = 480/40 = 12 metres/minute, or 0.2 metres/second
Angela's unit rate of swimming is 12 meters per minute, which converts to 0.2 meters per second. This is calculated by dividing the total distance by the total time. So, she swims at a constant speed of 12 m/min or 0.2 m/s.
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