Question

A projectile is fired from ground level with an initial speed of 250 m/sec and an angle of elevation of 30 degrees. Use that the acceleration due to gravity is 9.8 m/sec^2

The maximum height of the projectile is?

Answer 1

I have r(t) = (125sqrt(3)t) i + (125t - 4.9t^2) j

Answer 2

i thought I would take d/dt (125t - 4.9t^2), then set to 0 and solve for t but that didn't work

Answer 3

;)