You drive a beat-up pickup truck along a straight road for 8.4 km at 70 km/h, at which point the truck runs out of gasoline and stops. Over the next 30 min, you walk another 2.0 km farther along the road to a gasoline station. What is your average velocity from the beginning of your drive to your arrival at the gasoline station?

v_avg = 37 km/h

Explanation:

To find the average velocity in the complete trajectory you use the following formula:

  ( 1 )

v1: velocity in the first part of the trajectory = 70 km/h

v2: velocity in the second part of the trajectory = ?

You calculate v2 by using the following equation for a motion with constant velocity:

you replace the values of v1 and v2 in (1) and you obtain:

hence, the average velocity is 37 km/h

v = 16.8 km/h

Explanation:

The average velocity can be calculated usign the following equation:

Where:

Δx: is the change in the displacement

Δt: is the change in the time

The total displacement is:

The initial time is:

The total time is:

Finally, by taking:

Δt = 0.62 h

Δx= 10.4 km

The average velocity is:

Therefore, the average velocity is 16.8 km/h.

I hope it helps you!                  

the results is a decrease in air temperature with an increase of altitude.

explanation: