Question

A free-falling projectile is launched from the ground and has a hangtime of 6 seconds before hitting the ground. How high did it go?

Answer 1

1A)

x=v0x*t=v0cosθ*t

x=52co31*3.2=142.6 m

1B)

y0=1/2gt^2-v0y*t=1/2gt^2-v0sinθt

y=0.5*9.8*3.2^2-52*sin31*3,2=23.4 m

2A)

x=2v0^2sin(2θ)/g

v0=[xg/2sin(2θ)]^1/2=14.4 m/s

the initial speed relative to the ground is

v=v0-4.4=10 m/s

2B)

fly time is

t=2voy/g

t=2*14.4/9.8=2.94

2C)

mgy=1/2mv0y^2

y=v0y^2/(2g)=10.58 m