A person walking across the room with a constant speed of 2m/s, and they run back with a constant speed of 8m/s. What is their average speed for the trip? I know the answer is 3.2m/s but I need help knowing how it's done. Greatly appreciated!
average speed=distancetotal/time
Let L be the length of the room, then distance total=2L
but L= 8m/s*timeback
and L= 2m/s*timethere
L/8=timeback
L/2=timethere
add the equations
L(1/8+1/2)=total time
L(5/8)=total time
avgspeed=2L/totaltime=16/5=..