Distinguish between instantenous speed and average speed.A man drives a car at distance of 200km at an average speed of 44km per hour .What must be his average speed for the next 220km if he is to cover the total distance in 9hours
2 answers
Divide 200 km by 44 kmh to determine the time it took to go that far. Subtract that from 9. That is the time remaining. Now, how fast must the driver go to travel 220 km in that remaining time? Divide 220 by the remaining time.
T1 = d1/V1 = 200/44 = 4.55 h.
T2 = 9-4.55 = 4.45 h.
V2 = d2/T2 = 220/4.45 = 49.44 km/h.
T2 = 9-4.55 = 4.45 h.
V2 = d2/T2 = 220/4.45 = 49.44 km/h.