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The air resistance for a particular vehi...

The air resistance for a particular vehicle is proportional to square of its velocity. The ratio of power required at 40 km/hr to that reqd.at 80 km/hr is:

A

`1:1`

B

`1:2`

C

`1:4`

D

`1:8`

Text Solution

Verified by Experts

The correct Answer is:
d
`F prop v^(2)implies F = kv^(2)`. Now `P=Pv=kv^(3)`
`:. (P_(1))/(P_(2))=((v_(1))/(v_(2)))^(3)=(40/80)^(3)=1/8`.
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