Hard Projectile Motion Question Please Help (1 Viewer)

[hirschyboy]

A ball is shot from a cannon on a hill that is 1.93m high and lands 17.34m away after 1.586s what was the initial velocity of the ball?

I feel as if there is to little information please help

 

[Fizzy_Cyst]

A ball is shot from a cannon on a hill that is 1.93m high and lands 17.34m away after 1.586s what was the initial velocity of the ball?

I feel as if there is to little information please help

Use range equation to determine Ux

Use DELTAy = Uyt + 1/2ayt^2 to determine uy

You then have your two initial components and you can determine initial velocity

 

[asianese]

I got around 200.3m using ^'s method...

Remember its just a horizontal shoot off so there is no extra DeltaY to consider!!

 

[bleakarcher]

i did this problem yesterday and remember getting like 12m/s or so. ^ you can not assume the cannon is fired horizontally also.

 

[clementc]

Just to check, I got 15.1 m/s at an angle of 43.6° to the horizontal =D
Fizzy Cyst's method is right I think

 

[mezza333]

Sx=Uxt
Therefore 17.34 = Ux(1.568)
Ux=10.93ms-1

Sy=Uyt + 1/2ay(t^2)
-1.93=Uy(1.586) - (0.5x9.8x1.586^2)
Therefore Uy = 6.55 ms-1

U = √((10.93^2) + (6.55^2))
= 12.75ms-1
angle = tan^-1 (6.55/10.93)
= 30º56'

Therefore U = 12.75m/s at 30º56' above horizontal