A train starts from station A with uniform acceleration $$a1$$ for some distance and then goes with uniform retardation $$a2$$ for some more distance to come to rest at station B. The distance between stations A and B is $$4$$ km and the train takes $$1/15$$ h to complete this journey. If accelerations are in km per sq. minute unit, then $$1a1+1a2=x$$. Find the value of x.

Question

A train starts from station A with uniform acceleration $$a1$$ for some distance and then goes with uniform retardation $$a2$$ for some more distance to come to rest at station B. The distance between stations A and B is $$4$$ km and the train takes $$1/15$$ h to complete this journey. If accelerations are in km per sq. minute unit, then  $$1a1+1a2=x$$. Find the value of x.

Infinity Learn · Accepted Answer

$$t1+t2=4min$$,$$v=a1t1=a2t2S=12$$×$$4v$$⇒$$4=2v$$⇒$$v=2t1+t2=v1a1+1a2$$⇒$$4=21a1+1a2$$⇒$$1a1+1a2=2$$

Rectilinear Motion

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$t_{1} + t_{2} = 4 min, v = a_{1} t_{1} = a_{2} t_{2}$
$S = \frac{1}{2} \times 4 v \Rightarrow 4 = 2 v \Rightarrow v = 2$
$t_{1} + t_{2} = v [\frac{1}{a_{1}} + \frac{1}{a_{2}}]$
$\Rightarrow 4 = 2 [\frac{1}{a_{1}} + \frac{1}{a_{2}}] \Rightarrow \frac{1}{a_{1}} + \frac{1}{a_{2}} = 2$

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Rectilinear Motion

Remember concepts with our Masterclasses.

t1+t2=4min,v=a1t1=a2t2S=12×4v⇒4=2v⇒v=2t1+t2=v1a1+1a2⇒4=21a1+1a2⇒1a1+1a2=2

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$t_{1} + t_{2} = 4 min, v = a_{1} t_{1} = a_{2} t_{2}$
$S = \frac{1}{2} \times 4 v \Rightarrow 4 = 2 v \Rightarrow v = 2$
$t_{1} + t_{2} = v [\frac{1}{a_{1}} + \frac{1}{a_{2}}]$
$\Rightarrow 4 = 2 [\frac{1}{a_{1}} + \frac{1}{a_{2}}] \Rightarrow \frac{1}{a_{1}} + \frac{1}{a_{2}} = 2$