Question

On planet Jerousek, which has almost no atmosphere, the acceration due to gravity is 10.5 m/s2m/s2.A projectile is launched from the top of a steep hill with an initial velocity of 30 m/s at an angle of 43º from the horizon. The projectile takes 14 s to hit the ground at the bottom of the hill. (Neglect air resistance)

Part A - How long does it take for the projectile to reach the ground?

t =	nothing	s

Part B - What is the y-component of the projectile's initial velocity?

v0yv0y =	nothing	m/s

Part C - How tall is the hill?

h =	nothing	m

Part D - How far horizontally from the base of the launch-point on the hill does the projectile land?

ΔxΔx =	nothing	m

Answer 1

acceleration due to gravity g = 10.5 m/s2 ; initial velocity u = 30 m/s and angle of projection is 43o above horizontal. The time taken by the projectile to reach the bottom of the hill is t = 14s.

Part A) The time taken to reach the ground is t = 14s

Part B) The initial horizontal veloity is ux = u cos = 30 x cos 43o = 21.94 m/s

The initial vertical veloity is uy = u sin = 30 x sin 43o = 20.46 m/s

Part C) The height of the hill is vertical displacement of the projectile. y = u sin t - 1/2 g t2

y = 20.46 x 14 - 0.5 x 10.5 x 196 = - 742.56 m

The height of the hill is 742.56 m

Part D) The horizontal range R = u cos t = 21.94 x 14 = 307.16 m

The projectile lands horizontally at a distance of 307.16 m from the base of launch point on the hill.