A car travels on a straight road fr 10 km at 10 m/s. It then speeds up and travels another 10 km at 30 m/s. What is the average speed for the entire 20 km trip

Question

A car travels on a straight road fr 10 km at 10 m/s. It then speeds up and travels another 10 km at 30 m/s. What is the average speed for the entire 20 km trip?

 

Average speed is the total distance / total time.

Answer 1

for first car

10 km =10,000 m

 

speed = distance /time

 

10   =10000/t

 

t= 10000/10=1000 seconds

 

for second car

 

 

30 = 10,000 / t

t =333 seconds

 

Average speed =the total distance / total time.

 

                     =  (10,000+10,000 ) / (1000+333)

                     

                     = 20,000 /1333

                    =15.03 meter/ seconds