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 moves together. Determine their velocity

Answer 1

Hello friend

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Given:

Mass of bullet(m1) = 10g = 10/1000 kg

= 0.010 kg

Mass of plank(m2) = 90g = 0.090 kg

Initial velocity of bullet (u1) = 1.5 m/s

Initial velocity of plank(u2) = 0 m/s

We have to find,

The final velocity (v1 and v2) = ?

Let the common velocities of the bullet and plank .

v1 = v2 = v

by using the formula,

m1u1 + m2u2 = m1v1 + m2v2

By putting the values,

(0.01 x 1.5) + (0.09 x 0) = (0.01 x v) + (0.09 x v)


0.015 + 0 = v(0.01 + 0.09)

0.015 = 0.1v

v = 0.015/0.1

v = 0.15 m/s


Therefore, the plank moves with a velocity of 0.15 m/s.


Thanks..


:)