Using a 1.5kW microwave for 10 minutes or a 30W CD player for 3 hours?

maria has a savings account that is earning simple interest. if she started with $200 in the account and has earned a total of $8 in interest in two years, what is the rate of the account? use the formula  .

12.50.080.001250.02

If element x has 21 protons, element x has 21 electrons

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.