Question

Consider the motion of a projectile. It is fired at t = 0. Its initial speed is 17 m/s and its initial projection angle is 35◦ from the horizontal.

What is the maximum height of its tra- jectory? The acceleration due to gravity is 9.8 m/s2 .
Answer in units of m.

Answer 1

vertical problem only
Vi = 17 sin 35 = 9.75
initial kinetic energy = (1/2) mVi^2
potential energy at top = m g h
so
g h = 1/2 Vi^2
h = VI^2/(2 g) = 9.75^2/(2*9.8) = 4.85
pathetic projectile :(

Answer 2

the initial vertical velocity is ... 17 m/s * sin(35º)

h = -4.9 t^2 + [17 * sin(35º)] t

max h is on the axis of symmetry ... t = [-17 sin(35º)] / (2 * -4.9)

Answer 3

thank you guys!