Answer:
average speed = 7.50 m/s
Step-by-step explanation:
given data
distance = 200 m
time = 10 seconds
passed = 50m
already gone = 60 m
to find out
average velocity need to be for the remaining time
solution
we get here first Velocity of friend v that is express as
velocity =

velocity =

velocity = 6 m/s
and time taken to reach half the way is here as
time taken =

time taken = 16.67 seconds
and now distance to be covered is
distance to be covered = 100 m - 50 m
distance to be covered = 50 meters
and remaining distance cover in time = 16.67 sec - 10 sec
remaining distance cover in time = 6.67 seconds
so average speed will be here as
average speed =
average speed = 7.50 m/s