The velocity of a particle is given by `v=(5t^(2)-6t+5)m//s` where t is time in seconds. Find its acceleration at t=4 second.

Answer

B, C, D

Explanation

Range `=(u^(2) sin 2theta)/(g)`
For `theta` & `(90-theta)` angles, rang will same so for `30^(@)` & `(90-30^(@))equiv60^(@)`, projections both strike at the same point. For time of flight, vertical components are responsible
`h_(1)/h_(2)=(u^(2) sin^(2) theta_(1))/(u^(2) sin^(2) theta_(2))=(sin^(2) 30)/(sin^(2) 60)=1/3`