Answer:
Vx = 15V
Step-by-step explanation:
To find the speed of the third car you take into account that the distance that they travel is the same. Only time is different in one second. Mathematically you have:
![x=3vt\ \ \ \ \ (1)\\\\x=5v(t-1)\ \ \ \ (2)\\\\x=v_x(t-2)\ \ \ \ (3)](https://img.qammunity.org/2021/formulas/physics/high-school/u0j5vtdtwkdn3ue6mgvmazoveg2obtdwvg.png)
you equal the first and second equation obtain the time t:
![3vt=5v(t-1)\\\\3t=5(t-1)\\\\3t=5t-5\\\\t=(5)/(2)s=2.5s](https://img.qammunity.org/2021/formulas/physics/high-school/drfoabrl28guj2om5028l9z94xl6udu24v.png)
then, you can equal the third and first equation:
![3vt=v_x(t-2)\\\\3(2.5s)v=(2.5s-2s)v_x\\\\7.5v=0.5v_x\\\\v_x=15v](https://img.qammunity.org/2021/formulas/physics/high-school/rwue8lm4nz4gvysg33cgog8s99horph81f.png)
hence, Vx = 15V
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TRANSLATION:
Para encontrar la velocidad del tercer automóvil, tenga en cuenta que la distancia que recorren es la misma. Solo el tiempo es diferente en un segundo. Matemáticamente tienes:
iguala la primera y segunda ecuación obtiene el tiempo t:
entonces, puedes igualar la tercera y primera ecuación:
por lo tanto, Vx = 15V