For what angle range becomes double of height in a projectile motion?

1 Answer
Jun 9, 2018

tan^-1 2tan12

Explanation:

The range for projectile is R = u^2/g sin(2 alpha)R=u2gsin(2α)
and the maximum height is given by H = (u^2sin^2 alpha)/(2g)H=u2sin2α2g

Thus, to get R = 2HR=2H we must have

u^2/g sin(2 alpha) = 2(u^2sin^2 alpha)/(2g) impliesu2gsin(2α)=2u2sin2α2g

sin(2alpha) = sin^2 alpha impliessin(2α)=sin2α

2sin alpha cos alpha = sin^2 alpha implies2sinαcosα=sin2α

tan alpha = 2 tanα=2

Thus, the angle of projection must be tan^-1 2tan12