Question

A particle is projected with a speed of 39.2m/sec at an elevation of 30degrees.find its greatest height.

Answer 1

at max height, v=0

sin 30 = 1/2, so the velocity is given by

39.2/2 - 9.8t = 0
t = 4

So, it rose for 4 seconds to max height.

Now recall that the height is given by

h = 39.2t - 4.9t^2

Just plug in t=4

Answer 2

How did you get 9.8t pls