A railway compartments is `16 m` long, `2.4 m` wide and `3.2 m` high. It is moving with a velocity `v` A particle moving horizontally with a speed `u` perpendicular to the direction of `v` enters through a hole at an upper corner `A` and strikes the diagonally opposite corner `B`.Assume `g=10 m//s^(2)`.

Options

A. `v=20m//s`
B. `u=3m//s`
C. to an observer inside the compartment the path of the particle is a parabola
D. to a stationary observer outside the compartment the path of the particle is a parabola

Answer

A, B, C, D

Explanation

Time of flight

`rArr =sqrt((2h)/(g))=sqrt((2xx32)/(10))=0.8sec. `
`y=V_(y)t`
`=2.4=Uxx0.8, U = 3m//s`
`x=V_(x)t`
`rArr 16=Vxx0.8, V=20m//s`
Angle between `vec(a) & vec(v)` is other then `0^(@)` or `180^(@)`, and `vec(a)` is constant . So the path will be parabola.