A 90 m long train is running a speed of 54 km-hr- If it takes 30 seconds to cross a platform- the length of the platform-120 m360 m480 m240 m

Question

Toppr Admin · Accepted Answer

Let length of platform-lmTotal distance-l-90-mNow- speed-Distancetime-x21D2-84-xD7-10003600-l-9030-x21D2-l-9030-15-x21D2-l-450-x2212-90-360m-x2234-Length of platform -360m

A $90$ m long train is running at a speed of $54$ km/hr. If it takes $30$ seconds to cross a platform, find the length of the platform.
$120$ m
$360$ m
$480$ m
$240$ m

Let length of platform $= l m$
Total distance $= (l + 90) m$
Now, speed $= \frac{D i s t a n c e}{t i m e} \Rightarrow \frac{84 \times 1000}{3600} = \frac{l + 90}{30}$
$\Rightarrow \frac{l + 90}{30} = 15 \Rightarrow l = 450 - 90 = 360 m$
$∴$ Length of platform $= 360 m$

A 90 m long train is running at a speed of 54 km/hr. If it takes 30 seconds to cross a platform, find the length of the platform.120 m360 m480 m240 m

Let length of platform=lmTotal distance=(l+90)mNow, speed=Distancetime⇒84×10003600=l+9030⇒l+9030=15⇒l=450−90=360m∴Length of platform =360m

A $90$ m long train is running at a speed of $54$ km/hr. If it takes $30$ seconds to cross a platform, find the length of the platform.
$120$ m
$360$ m
$480$ m
$240$ m

Let length of platform $= l m$
Total distance $= (l + 90) m$
Now, speed $= \frac{D i s t a n c e}{t i m e} \Rightarrow \frac{84 \times 1000}{3600} = \frac{l + 90}{30}$
$\Rightarrow \frac{l + 90}{30} = 15 \Rightarrow l = 450 - 90 = 360 m$
$∴$ Length of platform $= 360 m$