If a train is 100 kilometers away, how much sooner would you hear the train coming by listening to the rails (iron) as opposed to listening for it standing by the track? in other words, how much faster will the sound travel through the iron rails than through the air? assume the air temperature is 0°c. sound will reach you seconds sooner.

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? yourunits 3. a clothes dryer uses about 2 amps of current from a 240 volt line. how much power does it use? yourunits 4.

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?

Astronomers studying the planet of rhombus have detected sedimentary rock on its surface. one astronomer wonders if material in this sedimentary rock used to be in igneous rock deep in rhombus’s interior. can igneous rock become sedimentary rock? explain your answer.