projectile motion (urgent)

45. divide projectile into vertical + horizontal, only need to look at vertical

see at 36, .09m

work out vertical distance 0.9 * sin(36)

next thing, find vertical projectile, when launched at speed x, will achieve vertical height of insect 0.9 * sin(36)

then find the split angle of x and 3.56

sin(a) * 3.56 = x
a = sin-1(x / 3.56)


49, answer for a is wrong, its not 11.3 - 9
we are not working on a prejump, we are working on jump
to solve the whole question, tilt the gravitational force by 11.3 degree, and only look at the projectile question as if it is on a horizontal land (the steep slope of 11.3 degree), "vertical" downard gravitation force = g * cos(11.3), "horizontal" forward acceleration force = g * sin(11.3)

51, first off, I think it is the american football, you don't score on the ground, you score when the ball flies above the goal post.
so you must solve a low angle, but ball arrive at 3.44m goal post after travelling 50m projectile

53. solve for the vertical position when the horizontal position of the projectile is multiples of 20.3cm, when vertical position dips below the stair level, it has landed.