`W_(1),W_(2)` and `W_(3)` are the different sizes of windows `1, 2,` and `3` respectively placed in a vertical plane. A particle is thrown up in the vertical plane. Let `t_(1),t_(2)` and `t_(3)` are the time taken to cross the window `W_(1), W_(2)` and `W_(3)` respectively and `DeltaV_(1), DeltaV_(2)` and `DeltaV_(3)` are the change in speed after respective window cross.

Options

A. Average speed of the particle passing the windows may be equal if `W_(1)ltW_(2)ltW_(3)`
B. Average speed of the particle passing the windows may be equal if `W_(1)gtW_(2)gtW_(3)`
C. If `W_(1)=W_(2)=W_(3)`, the change in speed of the particle while crossing the windows will satisfy `DeltaV_(1)ltDeltaV_(2)ltDeltaV_(3)`
D. If `W_(1)=W_(2)=W_(3)`, the time taken by particle to cross the windows will satisfy `t_(1)lt t_(2) lt t_(3)`

Answer

A, C, D

Explanation

As going up, speed of the particle is decreasing and hence the time taken in crossing the windows will be `t_(1)lt t_(2) lt t_(3)` (if `W_(1)=W_(2)=W_(3)`)
Simultaneously `DeltaVpropt`
`:.DeltaV_(1)ltDeltaV_(2)lt DeltaV_(3)`
For unequal windows `t_(1)=t_(2)=t_(3)` may be if `W_(3)ltW_(2)ltW_(1)`