Helppp!! The diagram below shows a simple motor. The loop of wire is attached to the split-ring commutator.
a. Does the current flow through the wire from A-B or from B-A?
b. The current running through the loop will cause it to spin. Will this cause point A
to move up or down? How do you know?
c. What is the purpose of the split-ring commutator and why must it be used on the
motor for it to work properly?

Answervery high orbital velocities in a very compact region;

Can you give more detail  

Jenny and fred both play a long note on their trombones. a stationary observer hears the sound increasing and decreasing repeatedly in loudness. which of these must be true? the sound waves from the two trombones have slightly different frequencies.the sound waves from the two trombones have the same frequency.the sound waves from the two trombones have slightly different amplitudes.the sound waves from the two trombones have the same wavelength.the sound waves from the two trombones have slightly different velocities.  lolthe answer is          the sound waves from the two trombones have slightly different frequencies.