A BB gun is fired at a cardboard box of mass m2 = 0.85 kg on a frictionless surface. The BB has a mass of m1 = 0.0185 kg and travels at a velocity of v1 = 89 m/s. It is observed that the box is moving at a velocity of v2 = 0.32 m/s after the BB passes through it.

Respuesta :

Answer:

The magnitude of the BB's velocity is 74.29 m/s.

Explanation:

Given that,

Mass of BB [tex]m_{1}= 0.0185\ kg[/tex]

Mass of box [tex]m_{2}=0.85\ kg[/tex]

Velocity of gun [tex]v_{1}=89\ m/s[/tex]

Velocity of box [tex]v_{2}=0.32\ m/s[/tex]

Suppose write an expression for the magnitude of the BB's velocity as it exits the box [tex]v_{f}[/tex].

Using conservation of momentum

[tex]m_{1}u_{1}+m_{2}u_{2}=m_{1}v_{1}+m_{2}v_{2}[/tex]

Put the value into the formula

[tex]0.0185\times89+0=0.0185\times v_{1}+0.85\times0.32[/tex]

[tex]\dfrac{1.6465-0.272}{0.0185}=v_{1}[/tex]

[tex]v_{1}=74.29\ m/s[/tex]

Hence, The magnitude of the BB's velocity is 74.29 m/s.