Two trains of distance 100 km travelling towards each other at train a at 60 km/hr and train b at 40km/hr when a bird sitting on train a goes at a speed of 90km/hr starts moving towards train b from train a starts and comes back and forth. find the total distance travelled by the bird

no. dot product   =0 when vecs at right angles

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.

what is the actual question though?

pretty sure it's false