Waves that move the particles of the medium parallel to the direction in which the waves are traveling are called?

What is the temperature in degrees celsius of a substance with a tempature of 49k

A10nc charge sits at a point in space where the magnitude of the electric field is 1500 n/c. what will the magnitude of the field be if the 10 nc charge is replaced by a 20 nc charge? assume the system is big enough to consider the charges as small test charges.

Of is j/kg·k. if a 2.6 kg of isk to k,is ?