A4.25 g bullet traveling horizontally with a velocity of magnitude 375 m/s is fired into a wooden block with mass 1.20 kg , initially at rest on a level frictionless surface. the bullet passes through the block and emerges with its speed reduced to 128 m/s. how fast is the block moving just after the bullet emerges from it?

The block moves with a speed of 0.875 m/s just after the emergence of the bullet from the block.

Solution:

Mass of the bullet, m = 4.25 g = 0.00425 kg

Initial velocity of the bullet, u = 375 m/s

Mass of the wooden block, M = 1.20 kg

Initial velocity of the block, v = 0

Final velocity of the bullet, u' = 128 m/s

Now,

Let the final velocity of the block be v'.

Using the principle of conservation of the momentum:

mu + Mv = mu' + Mv'

v' = 0.875 m/s

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

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.