Answer:
A
Explanation:
just took a test on ed sorry if wrong I got it right
Alternating current (AC) flows half the time in one direction and half the time in the other, changing its polarity 120 times per second with 60-hertz current.
The formula for working out speed is distance ÷ time.
55 km ÷ 2 hours = 27.5 km/h (average speed for first part of journey)
52km ÷ 5 hours = 10.4 km/h (average speed for second part of journey)
(27.5 + 10.4) ÷ 2 = 18.95 km/h (average speed throughout the journey)