Question

Eric walks 7 km East in 2 hours and then 2.5 km West in 1 hour.

___ km/hr is the average speed and ___ km/hr is the average velocity for the whole journey that Eric takes.

Answer 1

Average speed = 3.17 km/h and Average velocity = 1.5 km/h

Explanation:

It is given that,

Eric walks 7 km East in 2 hours and then 2.5 km West in 1 hour.

Average speed = distance/time

Distance = 7km + 2.5 km = 9.5 km

Time = 2 h + 1 h = 3 h

Average speed,

`s=(9.5\ km)/(3\ h)\\\\s=3.17\ km/h`

Average velocity = displacement/time

Displacement = 7 km +(-2.5 km) = 4.5 km

Average velocity,

`v=(4.5\ km)/(3\ h)\\\\v=1.5\ km/h`

So, 3.17 km/h is the average speed and 1.5 km/h is the average velocity for the whole journey that Eric takes.