Question

a bus is moving at a constant rate of 40 kilometre per hour for two hours and then at a constant rate of 50 kilometre per hour for two more or what is its average speed​

Answer 1

GiveN :

• A bus is moving at constant speed of 40 km/h for 2 hours
• And then it travels with speed of 50 km/h for next 2 hours.

To FinD :

• Average Speed

SolutioN :

For First Case :

• Time (T1) = 2 hours
• Speed (S1) = 40 km/h

⇒Speed = Distance/Time

⇒Distance (D1) = Speed * Time

⇒D1 = 40 * 2

⇒D1 = 80

∴ Distance travelled in first case is 80 km/h

_____________________________

In Second Case

• Time (T2) = 2 hours
• Distance (D2) = 50 km/h

⇒S2 = D2/T2

⇒D2 = S2 * T2

⇒D2 = 50 * 2

⇒D2 = 100 m

∴ Distance travelled in 2nd Case is 100 m.

___________________________

Now, use formula for Average speed :

⇒Average Speed = Total Distance/Total Time

⇒Average Speed = D1 + D2/T1 + T2

⇒Average Speed = 100 + 80/2 + 2

⇒Average Speed = 180/4

⇒Average Speed = 45

∴ Average speed is 45 km/h.

Answer 2

✯✯ QUESTION ✯✯

A bus is moving at a constant rate of 40 kilometre per hour for two hours and then at a constant rate of 50 kilometre per hour for two more or what is its average speed..

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✰✰ ANSWER ✰✰

✔For 1st Case : -

$\longmapsto\tt{Speed=40km/hr}$

$\longmapsto\tt{Time\:Taken=2\:hr}$

➥Using Formula : -

$\longmapsto\tt{\small{\boxed{\bold{\bold{\pink{\sf{Speed=\dfrac{Distance}{Time}}}}}}}}$

➥Putting Values : -

$\longmapsto\tt{40=\dfrac{Distance}{2}}$

$\longmapsto\tt{40\times{2}=Distance}$

$\longmapsto\tt\bold{Distance=80km/hr}$

☛So , The distance travelled is 80 km/hr..

_______________________

✔For Second Case : -

$\longmapsto\tt{Speed=50km/hr}$

$\longmapsto\tt{Time\:Taken=2\:hr}$

➥Using Formula : -

$\longmapsto\tt{\small{\boxed{\bold{\bold{\green{\sf{Speed=\dfrac{Distance}{Time}}}}}}}}$

➥Putting Values : -

$\longmapsto\tt{50=\dfrac{Distance}{2}}$

$\longmapsto\tt{50\times{2}=Distance}$

$\longmapsto\tt\bold{Distance=100km/hr}$

☛So , The distance travelled is 80 km/hr..

➥Now ,

$\longmapsto\tt\bold{Average\:Speed=\dfrac{Total\:Distance}{Total\:Time}}$

$\longmapsto\tt{\dfrac{80+100}{2+2}}$

$\longmapsto\tt{\cancel\dfrac{180}{4}}$

$\longmapsto\tt\bold{45km/hr}$

☛So , The average speed is 45km/hr...