A cannon fires two similar shells one after the other each with a velocity of 100 m/s at angles 60$^\circ$ and 30$^\circ$ respectively with the horizontal such that they both hit the target at the same time. The time interval between the firing of the two shells is (Acceleration due to gravity = 10 m/s²).
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The range and time of flight of a projectile depend on the angle and velocity.