A projectile has same range R for the two angles of projection. If `T_(1)` and `T_(2)` are the times of flight in two cases, then:

Options

A. `T_(1)T_(2)propR`
B. `T_(1)T_(2)propR^(2)`
C. `T_(1)T_(2)prop1/R`
D. `T_(1)T_(2)prop 1/R^(2)`

Answer

A

Explanation

Range is same for angle of projection `theta` and `(90-theta)`
`T_(1)T_(2)=(2usintheta)/g.(2usintheta(90-theta))/g`
`T_(1)T_(2)=(4u^(2)sinthetacostheta)/g^(2)`
`=2/g.(u^(2)sin2theta)/g=(2R)/g`
`implies T_(1)T_(2)prop R`