A woman on a ten-speed bike travels at 9 m/s relative to the ground as she passes a little boy on a tricycle going in the opposite direction. If the boy is travelling at 1 m/s relative to the ground, how fast does the boy appear to be moving relative to the woman?

the boy will appear to be moving at 10 m/s relative to the cyclist.

Explanation:

We need to use the concept of relative velocity (as vector quantities) due to motion in opposite directions.

If the cyclist moves at 9 m/s in one direction (let's assume positive direction in a linear axis) and the boy at 1 m/s in opposite direction, then we assign  a positive sign to the 9 m/s and a negative sign to the velocity of the boy.

The velocity difference will then be:

| 9 m/s - (-1 m/s) | = 10 m/s

Then, the boy will appear to be moving at 10 m/s relative to the cyclist.

im guessing the west of station b

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.