Respuesta :
To solve this problem, we know that the formula for average speed is:
average speed = total distance travelled / total time
Now let us first calculate for the total distance travelled. Calculating:
total distance travelled = (70 km / hr) * 2 hr + (63 km / hr) * 5 hr
total distance travelled = 140 km + 315 km
total distance travelled = 455 km
Now for the total time:
total time = 2 hours + 5 hours
total time = 7 hours
Hence, the average speed is therefore:
average speed = 455 km / 7 hours
average speed = 65 km / hr
The answer is 65 km/h
To solve you do [tex]Avg Speed = \frac{Total Distance}{Total Time}[/tex]
[tex]Total Distance:[/tex]
[tex]=2(70)+5(63)[/tex]
[tex]=140+315[/tex]
[tex]=455 km[/tex]
[tex]Total Time:[/tex]
[tex]=7 hours[/tex]
[tex]Average Speed:[/tex]
[tex]=455[/tex]÷[tex]7[/tex]
[tex]=65 km/h[/tex]