Question

N automóvil corre a 120 kilómetros por hora y otro a 80 kilómUetros por hora; si deben recorrer 960 kilómetros, ¿con cuántas horas de diferencia llega el primero del segundo?

Answer 1

4 hours

Explanation:

Both cars here travel with uniform motion (constant velocity), so the relationship between distance covered, time taken and speed is:

`t=(d)/(v)`

where

t is the time taken

d is the distance covered

v is the speed of the car

Here we have:

`v_1 = 120 km/h` (speed of the 1st car)

`v_2=80 km/h` (speed of the 2nd car)

d = 960 km is the total distance covered by each car

So for car 1, the time taken is:

`t_1=(960)/(120)=8 h`

While for car 2, the time taken is:

`t_2=(960)/(80)=12 h`

And so, the difference in arrival time between the two cars is:

`\Delta t =t_2-t_1 =12 -8 = 4 h`