The old-fashioned record player had two speeds: one for long-playing albums (lp) and one for singles. the turntable speed for lps was 33 1/3 rpm (revolutions per minute). this was equivalent to 100 revolutions every three minutes. the speed of a single was 45 rpm. suppose it took 4.0 seconds for the turntable to ‘speed up’ from 33 1/3 rpm to 45 rpm when a switch was pressed to change the speed. what would be this angular acceleration in rad/sec2?

Explanation:

initial frequency of revolution is given as

now initial angular speed is

Similarly final angular speed is given as

Now angular acceleration is given as

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.