A 0.03-kg bullet is fired with a horizontal velocity of 470 m/s and becomes embedded in block B which has a mass of 3 kg. After the impact, block B slides on a 30-kg carrier C until it impacts the end of the carrier. Knowing the impact between B and C is perfectly plastic and the coefficient of kinetic friction between B and C is 0.2, determine the velocity of the bullet and block B after the first impact and the final velocity of the carrier. (Round the final answer answers to two decimal places.)

Respuesta :

Answer with Explanation:

We are given that

Mass of bullet,[tex]m_1=0.03 kg[/tex]

[tex]u_1=470 m/s[/tex]

[tex]m_2=3 kg[/tex]

[tex]\mu_k=0.2[/tex]

[tex]m_3=30 kg[/tex]

We have to find the velocity of the bullet and block B after the first impact and final velocity of the carrier.

According to law of conservation of momentum

[tex]m_1u_1=(m_1+m_2)v[/tex]

[tex]0.03(470)=(0.03+3)v[/tex]

[tex]v=\frac{0.03(470)}{(0.03+3)}=4.65 m/s[/tex]

Hence, the velocity of the bullet and block B after the first impact=4.65 m/s

According to law of conservation of momentum

[tex](m_1+m_2)v=(m_1+m_2+m_3)V[/tex]

[tex](0.03+3)\times 4.65=(0.03+3+30)V[/tex]

[tex]V=\frac{(0.03+3)\times 4.65}{(0.03+3+30)}[/tex]

[tex]V=0.43 m/s[/tex]

Answer:

[tex]v_B=4.65\ m.s^{-1}[/tex] is  the velocity of the block and the bullet system after the first impact.

[tex]v_c=0.43\ m.s^{-1}[/tex] is the velocity of the carrier.

Explanation:

Given

mass of bullet, [tex]m=0.03\ kg[/tex]

horizontal velocity of bullet, [tex]v=470\ m.s^{-1}[/tex]

mass of block, [tex]m_B=3\ kg[/tex]

mass of carrier, [tex]m_c=30\ kg[/tex]

coefficient of kinetic friction between block and carrier, [tex]\mu_k=0.2[/tex]

Since the collision between the bullet and the block is perfectly plastic:

We have the conservation of linear momentum as:

[tex]m.v=(m+m_B).v_B=(m+m_B+m_c).v_c[/tex]

[tex]0.03\times 470=(0.03+3)\times v_B=(0.03+3+30)\times v_c[/tex]

[tex]v_B=4.6535\ m.s^{-1}[/tex] is  the velocity of the block and the bullet system after collision.

After the collision of block & carrier:

[tex]v_c=0.4268\ m.s^{-1}[/tex] is the velocity of the carrier.