Acar moving with an initial speed v collides with a second stationary car that is one-half as massive. after the collision the first car moves in the same direction as before with a speed v/3.(a) find the final speed of the second car.(b) is this collision elastic or inelastic?

(a)

Let's write the law of conservation of momentum for the collision:

(1)

where u refers to the initial velocities and v refers to the velocity after the collision.

The problem gives us the following information:

- car B is one-half as massive as car A, so we can write:

- car B is initiall stationary:

- After the collision, car A moves in the same direction as before with a speed v/3:

So we can rewrite (1) as

and solving for , we find the final speed of car B:

(b) Elastic

To find if the collision is elastic or inelastic, we have to check if the total kinetic energy has been conserved or not.

The total kinetic energy before the collision is:

The total kinetic energy after the collision is:

The total kinetic energy has been conserved: so, the collision is elastic.

small = small current large mag large current

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.