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todays puzzle:
A railway track circles the Earth, touching the ground at all locations.now the track length is increased by 5 metres.
(assume circumference of the Earth= 40,000 km).the track now blankets the earth and doesnt touch it(theoretically) and lies slightly above the ground at all locations
How far the track has risen?
(assume circumference of the Earth= 40,000 km).the track now blankets the earth and doesnt touch it(theoretically) and lies slightly above the ground at all locations
How far the track has risen?
Ans: (2.5/pi)m or 0.796m
ReplyDeletec1 = 2*pi*r1
c2 = c1+5 = 2*pi*r2
c2-c1 = c1+5 -c1 = 2*pi*(r2-r1)
r2-r1 = 5/(2*pi) = 0.796
approx. by 1m
ReplyDelete1 metre.
ReplyDelete2piR-2pir=5m
ReplyDeleteIt implies that R-r=5/2pi=0.8 metre
Circumference = 2 × pi × Radius
ReplyDeleteBefore: Original Circumference = 2 × pi × Radius
After: Original Circumference + 5m = 2 × pi × (Radius + Rise)
Subtracting the two:
5m = 2 × pi × Rise
So, Rise = 5m / (2 × pi) = 0.7957747m approximately
Circumference = 2 × pi × Radius
ReplyDeleteBefore: Original Circumference = 2 × pi × Radius
After: Original Circumference + 5m = 2 × pi × (Radius + Rise)
Subtracting the two:
5m = 2 × pi × Rise
So, Rise = 5m / (2 × pi) = 0.79577471m approximately
Therefore, the track should have risen 0.79577471m approximately
Answer is 2.5/Pi
ReplyDelete