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Mathews usually makes the 100 km journey to visit his family. The trip involves three separate stages:

a) A stage of 20 km that is travelled on small roads at a constant speed of 30 km/h.

b) A stage of 50 km that is travelled on the highway at a constant speed of 100 km/h.

c) A stage of 30 km that is travelled on standard roads at a constant speed of 40 km/h.

1- How long does it normally take Mathews to make this journey?

Last week there were roadworks on a section of the highway, and he was only able to travel at 60 km/h for the length of the roadworks. Matthews's journey last week took 6 minutes longer than usual.

2- What was the length of the section of roadworks?

Respuesta :

Answer:

1 . Total time = 1 hr 55 minutes

2 Distance = 121 km

Step-by-step explanation:

Mattew journey

stage a

Distance = 20km

Speed = 30km/h

Time = distance/speed

Time = 20/30

Time = 2/3 h

Time = 40 minutes

Stage b

Distance = 50 I'm

Speed = 100 km/h

Time = distance/speed

Time = 50/100

Time = 0.5 h

Time = 30 minutes

Stage c

Distance = 30 km

Speed = 40 km/h

Time = distance/speed

Time = 30/40

Time = 3/4 h

Time = 45 minutes.

Total time taken =( 40 + 30 + 45 ) minutes

Total time = 115 minutes

Total time = 1 hr 55 minutes

2.

Speed =60 km/h

Time= 6 minutes + x

And x = 1 hr 55 minutes

Time = 1 hr 55 minutes + 6 minutes

Time = 2 hr 1 minute

Time = 2.01666667 hr

Distance covered = speed * time

Distance = 60*2.016667

Distance = 121 km

lhmarianateixeira

In this exercise we have to use the knowledge of time and distance, so we have to:  

1) Total time = 1 hr 55 minutes

2) Distance = 121 km

 

To calculate Matthew's journey we have to use the formula of :

[tex]Time= \frac{Distance}{Speed}[/tex]

Are doing the calculations for each Stage, like this:

Stage A, we know that:

  • Distance: [tex]20\ km[/tex]
  • Speed: [tex]30\ km/h[/tex]

[tex]Time = 20/30\\T = 2/3 h\\Time = 40 \ minutes[/tex]

Stage B, we know that:  

  • Distance: [tex]50\ km[/tex]
  • Speed: [tex]100\ km/h[/tex]

[tex]Time = 50/100\\T = 0.5 h\\Time = 30\ min[/tex]

Stage C, we know that:  

  • Distance:  [tex]30 \ km[/tex]
  • Speed: [tex]40 \ km/h[/tex]

[tex]Time = 30/40\\T= 3/4 h\\Time = 45\ min[/tex]

1) So using all the values ​​calculated above, let's calculate the total value of the trip that will take place by:

[tex]Total =( 40 + 30 + 45 ) minutes\\Total = 115 \ minutes\\Total = 1 \ hr \ 55 \ minutes[/tex]

2) For the second part of this question we want to calculate the total distance of travel hours so:  

  • Speed: [tex]60 km/h[/tex]
  • Time: [tex]6 minutes + x[/tex]

[tex]x = 1 \ hr \ 55 minutes\\Time = 1 \ hr\ 55 \ minutes + 6 \ minutes = 2 \ hr \ 1 minute\\Time = 2.01666667\\Distance = speed * time\\Distance = 60*2.016667\\Distance = 121 km[/tex]

See more about time and disatnce at brainly.com/question/2570752

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