# Homework Help: Projectile Motion Question with Components

1. Dec 14, 2009

### electriceel

An artillery unit has a 105 mm howitzer with shells that leave the muzzle at Velocity 472 m/s. Firepower fixed but angle at which it is fired (60$$\circ$$) is not. A What should you do? Increase or decrease the angle? B As an artillery officer in physics training, where di the shot first land? determine time shell takes to reach max height and use that to figure out total time for shell to hit the ground

For A I know I have to decrease the angle, why? Not sure. Here's what I did for A

Vxo = 472 cos 60 = 236 m/s
Vyo = 472 sin 60 = 409 m/s

$$\theta$$ = 30$$\circ$$

B Time, Using 10 as g: Vy = Vyo - gT --> 0=409 - 10T ---> T= 40.9 seconds to max height.

And then I have no idea where to go from there.