A projectile is launched with a speed of an angle `60^@` with the horizontal from a sloping surface of inclination `30^@`. The range R is: `(g=10m//s^2)`

Options

A. (a)4.9 m
B. (b)13.3 m
C. (c)9.1 m
D. (d)12.6 m

Answer

B

Explanation

At B, `S_(y)=0, u_(y)t+1/2 a_(y)t^(2)=0`
`t=-(2u_(y))/(a_(y))=(-2(10))/(-10 xx sqrt3/2) =4/sqrt3s, AB=R=1/2 a_(x) t^(2)`
`R=1/2 (10xx 1/2) (4/sqrt3)^(2)=10/4 xx (16)/(3)=40/3=13.33m`