someone fires a 0.04 kg bullet at a block of wood that has a mass of 0.5 kg. (the block of wood is sitting on a frictionless surface, so it moves freely when the bullet hits it). the wood block is initially at rest. the bullet is traveling 300 m/s when it hits the wood block and sticks inside it. now the bullet and the wood block move together as one object. how fast are they traveling?

22.2 m/s

Explanation:

We can solve the problem by using the law of conservation of momentum. In fact, the total momentum before and after the collision must be the same, so we  can write:

where:

m = 0.04 kg is the mass of the bullet

u = 300 m/s is the initial velocity of the bullet, before the collision

M = 0.5 kg is the mass of the block

U = 0 is the initial velocity of the block

v is the velocity of the bullet+block after the collision, as they stick together

Solving for v, we find:

not too sure thinking it will always be directed towards the centre of the earth. could be wrong not sure

a.   mass number from atomic number