Projectile Motion Bomb Question

[pacesetter1]

Homework Statement

(b) A power hungry megalomaniac obtains mortar bomb capability. The device could fire 120.5kg mortar shells a maximum distance of 5321m when projected at 45° to the horizontal. What would the velocity of the shell be as it left the muzzle of the device?

(c) What was the maximum height reached by the shell?

Homework Equations

S=Ut + 1/2at^2
v^2=u^2 +2as
v=u+at

where s=distance, u=initial velocity, a= acceleration and t=time

The Attempt at a Solution

t=16.4s
u=229m/s
maximum height=1338m

Can anyone help me check if the solution is right. Thks

 

[NEILS BOHR]

just use the range formula , i.e R = u² sin 2\theta / g

and max ht = u² sin ² \theta / 2g