When tuning his guitar, a music student notices that the string is not vibrating at the desired frequency of 120 Hz, so he tightens the string by 15.5% to get this frequency. At what frequency was the string vibrating when he first started the tuning process

Abird sitting high in a tree is an example of what type of wnergy

Estimate the kinetic energy of mars with respect to the sun as the sum of two terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. (assume mars is a uniform sphere with mass = 6.4×10 to the power of 23 kg, radius = 3.4×10 to the power of 6 m, rotation period = 24.7 hours, orbital period = 686 days and is 2.3×10 to the power of 8 km from the sun.)

The center of the milky way most likely contains a. empty space. b. a red giant star. c. a globular cluster. d. a supermassive black hole.