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A frog sits on the end pf a long boord o...

A frog sits on the end pf a long boord of length L. the boord rests on a fricationless horizontal table. The frog wants os the minimum takes - off speed i.e relative to ground v that allows the frog yo do the trick? The board and the frog have equal masses.

Text Solution

Verified by Experts

The correct Answer is:
2
Apply conservation of momentum in horizontal direction

`mvcostheta-mu=0implies u=vcostheta`
`L-x, ut, xv=vcosthetat`
Solve to get `x=L/2`
`x=(v^(2)sin2theta)/gimpliesL/2=(v^(2)sin2theta)/g`
`implies v=((gL)/(2sintheta))` for minimum `v, sin 2theta=1`
`implies v=sqrt((gL)/2)=sqrt((10xx5)/2)=2ssqrt5m//s,` Hence `n=2`
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