Acannonball is launched from the ground at an angle of 30 degrees above the horizontal and a speed of 30 m/s. ideally (no air resistance) the ball will land on the ground with a speed of

As we know that here no air resistance while ball is moving in air

So here we will say that

initial total energy = final total energy

here we know that

(as it will be on ground at initial and final position)

so we will say

since mass is always conserved

so we will say that final speed of the ball must be equal to the initial speed of the ball

so we have