You run 100 meters at a speed of 5.0 m/s and then you walk 100 meters at a speed of 1.0 m/s. What is your average speed for this entire exercise period?

*d - distance*

*v - speed*

*t - time*

*d = st*

*t = d / v*

*v = d / t*

**~~~~~~~~~**d

_{1}= 100 m

v

_{1}= 5.0 m/s

t

_{1}= 100 / 5 = 20 (seconds)

d

_{2}= 100 m

v

_{2}= 1.0 m/s

t

_{2}= 100 / 1 =100 (seconds)

Average speed

v = (d

_{1}+ d

_{2}) / (t

_{1}+ t

_{2})

*= 200 / 120 = 5 / 3 ≈*

**v**

**1.7 m/s**