A ball is launched from ground level at 30 m/s at an angle of 35° above the horizontal. how far does it go before it is at ground level again

Explanation:

Ignoring air resistance

Initial vertical velocity is 30sin35 = 17.2 m/s

Gravity reduces this velocity to zero in a time of

t = v/g =17.2 / 9.8 = 1.755 s

it takes the same time to come back down to ground level for a total flight time of 2(1.755) = 3.51 s

The horizontal velocity is 30cos35 = 24.57 m/s

the distance traveled horizontally is

d = vt = 24.57(3.51) = 86.298... = 86 m

e/c, where e is its total energy