5. 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?

22.22 m/s

Explanation:

Using the law of conservation of momentum:

Initial momentum of the system = final momentum of the system.

mu+m'u' = mv+m'v'

where u and u' are the initial velocities.

v and v' are the final velocities.

mass of bullet, m = 0.04 kg

mass of the block of wood, m' = 0.5 kg

initial velocity of bullet, u = 300 m/s

initial velocity of block, u' = 0

after collision, block and bullet would move together with velocity v

⇒0.04 kg × 300 m/s + 0 = 0.54 kg × v

⇒ v = 22.22 m/s

Thus, the bullet and the wood block move together as one object with the speed 22.2 m/s.

the moon affects the earth gravitation ally, causing certain motions of that body and also producing tides in its ocean and atmosphere. the tidal wave in our atmosphere is, however, far too minute to be an effective cause in any known meteorological phenomenon.

explanation:

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )