contestada

Two trains left the cities A and B at the same time and headed towards each other. The cities are s miles apart. The first train was traveling at the speed of v1 mph. The second train was traveling at the speed of v2 mph. After t hours the two trains met each other. Find the formula for t in terms of s,v1 and v2. Then find the value of t if: s=310, v1 = 75, v2 = 80

Respuesta :

The formula of t in terms of s , [tex]v_{1}[/tex] , [tex]v_{2}[/tex] is

[tex]t=\frac{s}{(v_{1}+v_{2})}[/tex]

The value of t  when s = 310 , [tex]v_{1}[/tex] = 75 , [tex]v_{2}[/tex] = 80 is 2 hours

Step-by-step explanation:

Two trains left the cities A and B at the same time and headed towards

each other

  • The cities are s miles apart
  • The first train was traveling at the speed of [tex]v_{1}[/tex] mph
  • The second train was traveling at the speed of [tex]v_{1}[/tex] mph
  • After t hours the two trains met each other

∵ The cities are s miles apart

∵ After t hours the two trains met each other

∴ s = [tex]s_{1}[/tex] + [tex]s_{2}[/tex], where [tex]s_{1}[/tex] is the

   distance that the 1st train moved in t hours and [tex]s_{2}[/tex]

    is the distance that the 2nd train moved in t hours

∵ s = v t

∴ [tex]s_{1}[/tex] = [tex]v_{1}[/tex] t

∴ [tex]s_{2}[/tex] = [tex]v_{2}[/tex] t

- Substitute them in the equation of s

∴ s = [tex]v_{1}[/tex] t + [tex]v_{2}[/tex] t

- Take t as a common factor in the right hand side

∴ s = t ( [tex]v_{1}[/tex] + [tex]v_{2}[/tex] )

- Divide both sides by ( [tex]v_{1}[/tex] + [tex]v_{2}[/tex] )

∴ [tex]t=\frac{s}{(v_{1}+v_{2})}[/tex]

The formula of t in terms of s , [tex]v_{1}[/tex] , [tex]v_{2}[/tex] is

[tex]t=\frac{s}{(v_{1}+v_{2})}[/tex]

∵ s = 310 m/h

∵ [tex]v_{1}[/tex] = 75 m/h

∵ [tex]v_{2}[/tex] = 80 m/h

- Substitute these values in the formula of t above

∴ [tex]t=\frac{310}{(75+80)}=\frac{310}{155}[/tex]

∴ t = 2 hours

The value of t  when s = 310 , [tex]v_{1}[/tex] = 75 , [tex]v_{2}[/tex] = 80 is 2 hours

Learn more:

You can learn more about distance, speed and time in brainly.com/question/1748290

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