Question

Calculate speed of the train travelled of a distance of 120 km in 3 hours

Answer 1

Given

Distance ⇨ 120 km

Time ⇨ 2 hrs

We Have to Find Speed here

Using Formula ➞ Speed = Distance/Time

➧ 120/3

➧ 40

Therefore, the Speed of Train is 40 km/hr

Converting in m/s

We will Multiply by 5/18

Therefore,

➡ 5/18 × 40

➡ 200/18

➡ 11.11 (approx)

Therefore, 11.12 m/s

Additional Information

Speed it the Rate of Change of position of an object with respect to time.

Distance is the length between Initial & Final path.

Important Formulas

• Speed = Distance/Time

• Distance = Speed × Time

• Time = Distance/Speed

• v² - u² = 2as

• v = u + at

• S = ut + 1/2at²

Answer 2

Answer

• Speed of train = 11.12 m/s

Given

• A train travelled a distance of 120 km in 3 hours

To Find

• Speed of the train

Concept Used

• Speed

• It is defined as distance covered per unit time

$\sf{\green{\bigstar \;\; Speed=\dfrac{Distance}{Time}}}\\\\\sf{\green{ \bigstar \;\; S=\dfrac{d}{t}}}$

• SI unit of speed is m/s
• SI unit of Distance is meter
• SI unit of Time is second

______________________

• 1 km = 1000 m
• 1 h = 60 min
• 1 min = 60 s
• 1 h = 3600 s

Solution

Case - 1 : In km/h

Distance , s = 120 km

Time , t = 3 h

Speed , S = ? m/s

Apply formula .

$\implies \rm Speed=\dfrac{Distance}{Time}\\\\\implies \rm S=\dfrac{d}{t}\\\\\implies \rm S=\dfrac{120}{3}\ km/h\\\\\implies \rm S=40\ km/h$

So , Speed of train is 40 km/h

________________________

Case - 2 : In m/s

Distance , d = 120 km

⇒ d = 120 × ( 1000 m )

⇒ d = 1,20,000 m

Time , t = 3 h

⇒ t = 3 × ( 60 min )

⇒ t = 180 min

⇒ t = 180 × ( 60 s )

⇒ t = 10800 s

Now apply formula .

$\implies \rm Speed=\dfrac{Distance}{Time}\\\\\implies \rm S=\dfrac{d}{t}\\\\\implies \rm S=\dfrac{120000}{10800}\\\\\implies \rm S=\dfrac{1200}{108}\\\\\implies \rm S=11.12\ m/s$

So , Speed of train is 11.12 m/s

More Info

$\boxed{\begin{minipage}{4cm} \bf Equations\ of\ motion\ :\\\\\rm \bigstar \;\; v=u+at \\\\\rm \bigstar \;\; s=ut+\dfrac{1}{2}at^2\\\\\rm \bigstar \;\; v^2-u^2=2as\\\\\rm \bigstar \;\; S_n=u+\dfrac{a}{2}[2n-1] \end{minipage}}$