Can someone pls help me

What produces a record of seismic waves? richter scale seismogram barometer seismograph

What is the measure of a change in an objects velocity?

Jenny wants to test the electrical conductivity of two substances dissolved in water. she is preparing the containers for the experiment. which factor is most important for her to control? a) volumes of the solutions b) appearance of the solutions c) temperatures of the solutions d) concentrations of the solutions