Bullet and Block#

Lorenzo fires a bullet of mass 21g into a block of mass 12kg that is initially at rest on a table.

The block, with the bullet embedded in it, slides across the table horizontally a distance of 6 cm. The coefficient of kinetic friction between the table and the block is 0.2.

Part 1#

What is the bullet’s initial speed before it hits the block?

Answer Section#

Please enter in a numeric value in m/s.

Part 2#

Lorenzo decides to repeat the experiment with a new block of wood. Unfortunately, Lorenzo does not have a weighing scale and does not know the mass of the new block. But because they took an undergraduate physics course, they know they can figure it out if they have the initial velocity of the bullet. They happen to have a ballistic chronograph that can capture the velocity of fast moving bullet. Just before it collides with the block, the bullet’s velocity is 855 m/s.

What is the mass of the new block (in kg) if it moves 6.6cm ?

Answer Section#

Please enter in a numeric value in kg.

Attribution#

Problem is licensed under the CC-BY-NC-SA 4.0 license.
The Creative Commons 4.0 license requiring attribution-BY, non-commercial-NC, and share-alike-SA license.