Answer:
v_avg = 37 km/h
Explanation:
To find the average velocity in the complete trajectory you use the following formula:
[tex]v_{avg}=\frac{v_1+v_2}{2}[/tex] ( 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:
[tex]v_2=\frac{2.0km}{30min}*\frac{60min}{1h}=4\frac{km}{h}[/tex]
you replace the values of v1 and v2 in (1) and you obtain:
[tex]v_{avg}=\frac{70km/h+4km/h}{2}=37\frac{km}{h}[/tex]
hence, the average velocity is 37 km/h
Answer:
v = 16.8 km/h
Explanation:
The average velocity can be calculated usign the following equation:
[tex] v = \frac{\Delta x}{\Delta t} [/tex]
Where:
Δx: is the change in the displacement
Δt: is the change in the time
The total displacement is:
[tex]x_{t} = 8.4 km + 2.0 km = 10.4 km[/tex]
The initial time is:
[tex] t = \frac{x}{v} = \frac{8.4 km}{70 km/h} = 0.12 h [/tex]
The total time is:
[tex]t_{t} = 0.12 h + 30min*\frac{1 h}{60 min} = 0.62 h[/tex]
Finally, by taking:
Δt = 0.62 h
Δx= 10.4 km
The average velocity is:
[tex] v = \frac{10.4 km}{0.62 h} = 16.8 km/h [/tex]
Therefore, the average velocity is 16.8 km/h.
I hope it helps you!
