Question

6. A person travels at 40km/h for 2 hours and then travels 100 km at 50km/h. find the average speed​

Answer 1

$\Large{\bf{\green{\mathfrak{\dag{\underline{\underline{Given:-}}}}}}}$

• A person travels at 40km/h for 2 hours and then travels 100 km at 50km/h.

$\Large{\bf{\orange{\mathfrak{\dag{\underline{\underline{To \: Find:-}}}}}}}$

• Average speed of the person.

$\Large{\bf{\red{\mathfrak{\dag{\underline{\underline{Solution:-}}}}}}}$

First,

• The person travels 40 km/h for 2 hours.

• This means that he travels 40 km in 1 hr.

Then,

• Distance traveled in 2 hours =

• Speed * Time

• 40 * 2

• 80 km

Second,

• The person travels 100 km at 50 km/hr.

• This means that he travels 50 km in 1hr.

Then,

• Time required to travel 100 km =

• $\sf \dfrac{Distance}{Speed}$

• $\sf \dfrac{100}{50}$

• $\sf \dfrac{\cancel{100}}{\cancel{50}}$

• 2 hr.

Now,

• Average speed = ?

$\boxed{\pink{\sf Average \: speed \: = \: \dfrac{Total \: distance \: covered}{Total \: time \: taken}}}$

• Total distance covered =

• 1st distance + 2nd distance

• 80 km + 100 km

• 180 km

• Total time taken =

• 1st time taken + 2nd time taken

• 2hr + 2hr

• 4 hr

Substituting the values,

$\sf Average \: speed \: = \: \dfrac{Total \: distance \: covered}{Total \: time \: taken}$

$\sf Average \: speed \: = \: \dfrac{180}{4}$

$\sf Average \: speed \: = \: \dfrac{\cancel{180}}{\cancel{4}}$

$\textsf{Average speed = 45 km/hr.}$

Therefore,

• $\underline{\boxed{\therefore{\blue{\sf Average \: speed \: = \: 45 \: km/hr.}}}}$

$\Large{\bf{\purple{\mathfrak{\dag{\underline{\underline{Extra \: Information:-}}}}}}}$

Speed:-

• It is the ratio between the distance and time.

• It is a scalar quantity.

• $\sf Speed \: = \: \dfrac{Distance}{Time}$

Distance:-

• Distance is the movement of an object irrespective of direction.

• It is a scalar quantity.

Time:-

• The measure of a period during a action or movement.

• It is a scalar quantity.

Answer 2

Answer:

• 45 Km/h

Step-by-step explanation:

Given

• Speed₁ = 40 Km/h
• Time taken₁ =2 hours
• Distance₂ = 100 Km
• Speed₂ = 50 Km/h

To find

• Average speed

Solution

⇛ Speed₁ = 40 Km/h

⇛ Time₁ = 2 hours

⇛ Distance = Speed × Time

• 80 Km

⇛ ∴ Distance₁ = 80 Km/h

⇛ Speed₂ = 50 Km/h

⇛ Distance₂ = 100 Km

⇛ Time = Distance/Speed

• 100/50
• 2

⇛ ∴ Time₂ = 2 hours

Now,

• Average speed = Total distance/Total time
• Average speed = (80 + 100)/(4)
• Average speed = (180)/4
• Average speed = 45

∴ Average speed of the person is 45 Km/h.