Question

In projectile motion if vertical component of velocity is increased to two times, keeping horizontal component unchanged, then

Answer 1

Time of flight is $t=\frac{2u_y}{g}$

so when the vertical velocity doubled $u_y$ , time of flight will become twice.

Maximum height $h=\frac{u_y^2}{2g}$ So it will become four times

Horizontal range $R=u_{x}t$ , since we have doubled the vertical velocity , so the time will also be doubled and hence range will be twice

$tan\theta =\frac{u_y}{u_x}$

when $u_y$ is doubled

$tan{\theta }_1=\frac{2u_y}{u_x}=2tan\theta$