Respuesta :

Concept #1: Speed Formulae

We know the formulae:

[tex]\text{Speed} = \dfrac{\text{Distance}}{\text{Time}}[/tex]

Let us solve an example to understand the concept better.

Example:

Question: Find the speed of a car which travelled 12 km in 2 hours.

Solution:   We know the following

  • Car travelled (Distance): 12 km
  • Time travelled: 2 hours

Substitute the information provided into the speed formula:

[tex]\implies \text{Speed} = \dfrac{\text{Distance}}{\text{Time}}[/tex]

[tex]\implies \text{Speed} = \dfrac{\text{12 km}}{\text{2 hours}} = \boxed{6 \ \text{km/hour}}[/tex]

Therefore, the speed of the car is 6 kilometers per hour.

Concept #2: Distance Formulae

From the previous concept, we had:

[tex]\text{Speed} = \dfrac{\text{Distance}}{\text{Time}}[/tex]

Finding the distance formula through step-by step work:

Let Speed = S, Distance = D, and Time = T.

[tex]\implies \text{S} = \dfrac{\text{D}}{\text{T}}[/tex]

Multiply "t" on both sides:

[tex]\implies \text{S} \times \text{T}= \dfrac{\text{D}}{\text{T}} \times \text{T}[/tex]

[tex]\implies \text{S} \times \text{T}={\text{D}[/tex]

From the above work, we can say that Distance = Speed × Time.

Let us solve an example to understand the concept better.

Example:

Question: A train travelled from point A at a speed of 16 km/h in 2 hours to reach point B. Find the distance (Point A - Point B) travelled by the train.

Solution:   We know the following

  • Speed of train: 16 km/h
  • Time taken to travel from A to B: 2 hours

Substitute the information provided into the distance formula:

[tex]\implies \text{Distance = Speed} \times \text{Time}[/tex]

[tex]\implies \text{Distance = 16 km/h} \times \text{2 hours}[/tex]

⇒ Distance = 16 km × 2 = 32 km

Therefore, the train travelled 32 km to reach point B.

Concept #3: Time Formulae

From the previous concept, we had:

[tex]\text{Distance = Speed} \times \text{Time}[/tex]

Finding the time formula through step-by step work:

Let distance = D, speed = S, and time = T

[tex]\implies \text{D = S} \times \text{T}[/tex]

Dividing "S" both sides:

[tex]\implies \dfrac{\text{D}}{\text{S}} = \dfrac{\text{S} \times \text{T}}{\text{S}}[/tex]

[tex]\implies \dfrac{\text{D}}{\text{S}} = \text{T}[/tex]

From the above work, we can say that Distance/Speed = Time.

Let us solve an example to understand the concept better.

Example:

Question: A plane traveled 200 km at a speed of 100 km/h. How much time did it take to travel 200 km?

Solution:   We know the following

  • Distance travelled by the plane: 200 km
  • Speed of plane: 100 km/h

Substitute the information provided into the time formula:

[tex]\implies \text{Time} = \dfrac{\text{Distance}}{\text{Speed}}[/tex]

[tex]\implies \text{Time} = \dfrac{\text{200 km}}{\text{100 km/h}} = \dfrac{\text{2 km}}{\text{1 km/h}} = \boxed{\text{2 hours}}[/tex]

Therefore, it took 2 hours to travel 200 km at a speed of 100 km/h.

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