GENERAL KNOWLEDGE

Detailed explanation-1: -The range of a projectile when fired at 75∘ with the horizontal is 0.5km .

Detailed explanation-2: -Answer is (b) 1.0 km = u2 sin90°/g = u2/g.

Detailed explanation-3: -That means that the best way to launch a high-altitude projectile is to send it flying at a 90-degree angle to the ground-straight up.

Detailed explanation-4: -A launch at 45 degrees would allow the ball to remain in the air for a longer time, but it would then be launched at a lower horizontal speed at the start and it would slow down more because of the longer flight time. An additional aerodynamic force arises if the ball is spinning.