11.12 Example 12

A cannon of 1000 kg, shoot a projectile of 9 kg with a velocity of 500 m/s at 30 degrees above the horizontal. If the cannon is above a horizontal surface and is free to move, and is a rigid body, which is the velocity of the cannon after the shoot? Which is the normal applied to the floor? The shoot last 7 milliseconds.

Solution with FisicaLab

Erase the content of the chalkboard and select the SI system. And add the elements as show the image below:

To the element Stationary reference system write:

g

9.81

t

0.007

To the block:

Name

Cannon

m

1000

a

a

vi

0

vf

vf

d

d

Relative to

sf

To its normal force:

f

n

To the impulsive force produced to the shoot (the oblique force), write:

f

f

ang

30

To the element Mobile, the projectile that we call Bala (projectile), write:

Name

Projectile

m

9

vi

0

angi

0

vf

500

angf

30

Now through the element Momentum we apply the impulsive force to the object Projectile:

Object

Projectile

Imp

imp

ang

ang

fImp

f

Now click in the icon Solve to get the answer:

n = 331238.571 N ;  a = -556.731 m/s2 ;  vf = -3.897 m/s ;
d = -0.014 m ;  f = 642857.143 N ;  imp = 4500.000 N*s ;
ang = 30.000 degrees ;
Status = success.