Three blocks shown in move vertically with constant velocities The relative velocity of w.r.t `C` is `100m//s` upward and the relative velocity of `B` w.r.t A is `50m//s` downward. All the string are ideal The velocity of `C` with respect to ground is `125//x` calculate x
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Answer

2

Explanation

Let velocity of block `A,B` and `C` are `vecv_(A),vecv_(B)` and `vecv_(C),vecv_(A)-vecv_(C)=100hatj...(1)vecv_(B)-vecv_(A)=50hatj.(2)`
Now write constraint equation for pulley to get
`vecv_(B)-vecv_(p)=-(vecv_(C)-vecv_(p))` or `2vecv_(p)=vecv_(B)+vecv_(C)`
also `vecv_(p)=-vecv_(A)"Thus we get"vecv_(A)= (37.5 hatj) m//s`
`vecv_(B)(-12.5g)m//s,vecv_(C)=(-62.5hatj)m//s`
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