
Respuesta :
Answer:
The final speed of the rocket once the engine has fired is 29.16 m/s.
Explanation:
By the principle of momentum and amount of movement, we match the momentum data to the amount of movement and find the value of speed.
I=3.5 kg*m/s
m=120g= 0.12kg
V=?
I=F*t
F*t=m*V
I/m=V
(3.5 kg*m/s) / 0.12kg = V
V=29.16 m/s
Explanation:
The given data is as follows.
  J = 3.5 kg-m/s,   m = 120 g = 0.120 kg    (as 1 g = 0.001 kg)
It is known that formula to calculate impulse is as follows.
    J = [tex]m(v_{2} - v_{1})[/tex]
     [tex]0.120(v_{2} - v_{1})[/tex] = 3.5
   [tex]v_2 - v_1[/tex] = 29 m/s
So, [tex]v_{2} = 29 + v_{1}[/tex]
        = 29 + 0 = 29 m/s
Thus, we can conclude that final speed ([tex]v_{2}[/tex]) is 29 m/s.