A ball is projected with a velocity `20 sqrt(3) ms^(-1)` at angle `60^(@)` to the horizontal. The time interval after which the velocity vector will make an angle `30^(@)` to the horizontal is (Take, `g = 10 ms^(-2))`

A body is projected with a velocity u at an angle of 60^(@) to the horizontal. The time interval after which it will be moving in a direction of 30^(@) to the horizontal is

A projectile is thrown with a velocity of 20 m//s, at an angle of 60^(@) with the horizontal. After how much time the velocity vector will make an angle of 45^(@) with the horizontal (in upward direction) is (take g= 10m//s^(2))-

A projectile is thrown with a velocity of 20 m//s, at an angle of 60^(@) with the horizontal. After how much time the velocity vector will make an angle of 45^(@) with the horizontal (in upward direction) is (take g= 10m//s^(2))-