A sailboat travels 45km eastward at a speed of 20km/hr. The wind then drops, and the boat continues due east with a speed of 15km/hr for 25km.

a.How long did it take the boat to travel 55km?
b. What was the average velocity for the trip?

1 answer

a. T = d1/V1 + d2/V2 = 45/20 + 10/15 = 2.92 Hours.

b. T1 = d1/V1 = 45/20 = 2.25 Hours.
T2 = d2/V2 = 25/15 = 1.67 Hours.

Vavg=(d1+d2)/(T1+T2)=(45+25)/(2.25+1.67)
= 17.86 km/h.