Question

help me out pls fast​

Answer 1

Answer:

C = 2 (3.14)(2.1) or C = 13.2 meters (depending on how you are to round your answers...) Since the wheel goes around 75 times per minute, the wheel will travel approximately 990 meters per minute. In an hour (60 minutes) the train will travel 990(60) meters, or about 59400 meters

hahahaha I had found the answer

Answer 2

✪ Understanding the Question :-

Now we have been provided with the radius of the wheels of the train that is 2.1 m . And it makes 75 revolutions in one minute , means by this we can find the distance travelled by the train in 1 minute . To Find the distance travelled by the train in 1 minute we first need the find the Circumference of the wheels of the train . Then once we get the Circumference of the wheels we need to multiply the value with 75 and after doing this we can get the distance travelled by the train in one minute . We know that 1 hour = 60 minutes so if we Multiply the distance travelled by the train in 1 minute by 60 minutes we would get the distance travelled by the train in 1 hour . Then we can calculate the speed of the train by the formula Speed = Distance / Time

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$\LARGE\mathfrak{\underline{\underline\textcolor{aqua}{ Given :-}}}$

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$\qquad\tt{:}\longrightarrow\large\textsf{Radius of the Train = 2.1 m}$

$\qquad\tt{:}\longrightarrow\large\textsf{Revolution by the wheel in one minute = 75}$

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$\LARGE\mathfrak{\underline{\underline\textcolor{aqua}{To \; \; Find :-}}}$

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$\qquad\tt{:}\longrightarrow\large\textsf{Speed of the Train in km/hr = ?}$

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$\LARGE\mathfrak{\underline{\underline\textcolor{aqua}{Formulas :-}}}$

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$:\longrightarrow\boxed{\large\textsf\textcolor{purple}{ {\large\textsf\textcolor{purple}{Circumference}}_{\large\textsf\textcolor{purple}{( \; Circle \; )}} = \large\textsf\textcolor{purple}{2πr} }}\\\\\\ :\longrightarrow\boxed{\large\textsf\textcolor{purple}{ Speed = \cfrac{\large\textsf\textcolor{purple}{Distance}}{\large\textsf\textcolor{purple}{Time}} }}$

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$\LARGE\mathfrak{\underline{\underline\textcolor{aqua}{Solution :-}}}$

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↦ First we need to find the Circumference of the Wheel.

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$\large: \: \Longrightarrow\textsf{Circumference = 2πr}\\\\\\\large\textsf{ =2 × \cfrac{\large\textsf{22}}{\large\textsf{7}} × \large\textsf{2.1}}\\\\\\\large: \: \Longrightarrow\textsf{= 2 × 22 × 0.3}\\\\\\\large: \: \Longrightarrow\boxed{\textsf\textcolor{red}{Circumference = 13.2}}$

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∴ The Circumference of the wheel = 13.2 m .

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↦ Distance travelled by the train in 1 minute can be calculated by multiplying the circumference of the wheels by 75 .

$\qquad\tt{:}\longrightarrow\large\textsf{Distance travelled in 1 minute = 75 × 13.2}$

$\qquad\tt{:}\longrightarrow\large\textsf{= 990}$

∴ The Distance travelled by the train in 1 minute = 990 m .

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↦ Disatnce travelled by the train in 1 hour can be calculated by multiplying the Distance travelled in 1 minute × 60 , because 1 hour = 60 minutes .

$\qquad\tt{:}\longrightarrow\large\textsf{= 990 × 60}$

$\qquad\tt{:}\longrightarrow\boxed{\large\textsf\textcolor{red}{= 59400}}$

∴ The Distance travelled in 1 hour = 59400 m .

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➛ As 1km = 1000m

∴ 59400 m = 59.4 km .

∴ The Distance travelled in 1 hour = 59.4 km

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↦ Speed of the train :-

$\large\textsf{ Speed = \cfrac{\large\textsf{Distance}}{\large\textsf{Time}} }$

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• Distance = 59.4 km
• Time = 1 hr

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$\large\textsf{ = \cfrac{\large\textsf{59.4}}{\large\textsf{1}} }$

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$\qquad\tt{:}\longrightarrow\boxed{\large\textsf\textcolor{red}{∴ The speed of the train in km per hr = 59.4 km/hr}}$