Two birds move away from each other. Their speeds with respect to the air are equal. One bird calls the other with a note of frequency 550 Hz. The other bird hears the note with a frequency of 450 Hz. The speed of sound in the air is 350 m/s. How fast is each bird moving with respect to the air

Ateam of astronauts is on a mission to land on and explore a large asteroid. in addition to collecting samples and performing experiments, one of their tasks is to demonstrate the concept of the escape speed by throwing rocks straight up at various initial speeds. with what minimum initial speed vesc will the rocks need to be thrown in order for them never to "fall" back to the asteroid? assume that the asteroid is approximately spherical, with an average density p 3.84 x108 g/m3 and volume v 2.17 x 1012 m3 recall that the universal gravitational constant is g 6.67 x 10-11 n m2/kg2

Gunpowder residue is most likely to show up where on a shooters hands

What are the necessary conditions for fusion?