Aballistics test involves firing a 10.0g bullet horizontally into a 1.50kg wood block that is initially at rest. the bullet becomes lodged in the block, and you determine that they move together at a speed of 5.00m/s. with this information, determine the velocity of the bullet before it entered the block.

u= 755 m/s

Explanation:

Lets take

Velocity of bullet = u m/s

The velocity of system after collision ,v= 5 m/s

m= 10 g = 0.01 kg

M= 1.5 kg

From linear momentum conservation( because there is no any external force on the system)

Pi= Pf

m u  = ( m +m) v

0.01 x u= (1.5 + 0.01) x 5

u= 755 m/s

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s