A car travels a distance of 140 km at 70.0 km/hr. It then travels an additional distance of 60.0 km at 40.0 km/hr. The average speed is

Question

Quizplus · Accepted Answer

The total distance traveled is 140 km + 60 km = 200 km.

The time taken to travel the first 140 km is:

time = distance ÷ speed 
time = 140 km ÷ 70.0 km/hr 
time = 2.0 hours

The time taken to travel the next 60 km is:

time = distance ÷ speed 
time = 60 km ÷ 40.0 km/hr 
time = 1.5 hours

The total time taken is:

total time = 2.0 hours + 1.5 hours 
total time = 3.5 hours

The average speed is:

average speed = total distance ÷ total time 
average speed = 200 km ÷ 3.5 hours 
average speed = 57.1 km/hr

Therefore, the best choice is B, with an average speed of 57.1 km/hr.

A Car Travels a Distance of 140 Km at 70