a child poked hole on a closed bottle filled with water she observed that no water spurting out. then she opened the cap of the bottle and found that the the water started spurting. why is it so

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

However, had it been a real sound, the sound's pitch would have been increased by the doppler effect, since the falcon was moving the source of the sound. perpendicular to away from towards at the same speed as

Explain why electric current cannot exist if a current doesn't have a voltage source.