Question

A bullet having a mass of 10 g and
moving with a speed of 1.5 m/s,
penetrates a thick wooden plank of
mass 900 g. The plank was initially
at rest. The bullet gets embedded in
the plank and both move together.
Determine their velocity.
(Ans: 0.15 m/s)​

Answer 1

Correct Question :

›»› A bullet having a mass of 10 g and moving with a speed of 1.5 m/s, penetrates a thick wooden plank of mass 90 g. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.

(Ans: 0.15 m/s)

Answer :

›»› Velocity = 0.15 m/s

Given :

• Mass of bullet = 10g
• Speed of bullet = 1.5 m/s
• Mass of thick wooden plank = 900 g

To Calculate :

• Determine their velocity.

Calculation :

As we know that

$\tt{: \implies m_1v_1 = (m_1 + m_2)v}$

⠀⠀

$\tt{: \implies v = \dfrac{m_1 \: v_1}{(m_1 + m_2)}}$

⠀⠀

$\tt{: \implies v = \dfrac{10 \times \cancel{10^{-3}} \times 1.5}{(10 + 90) \times \cancel{10^{-3}}}}$

⠀⠀

$\tt{: \implies v = \dfrac{10 \times 1.5}{10 + 90} }$

⠀⠀

$\tt{: \implies v = \dfrac{15}{10 + 90} }$

⠀⠀

$\tt{: \implies v = \cancel{\dfrac{15}{100} }}$

⠀⠀

$\frak{: \implies \underline{ \boxed{ \pink{ \bf{v = 0.5}}}}}$