Because the speed of sound in air is approximately constant (does not depend on frequency or wavelength), we can calculate the speed of sound as long as we know the frequency and wavelength of just one sound wave. The frequency of the highest note on the piano is 4186 Hz and its wavelength is 0.082 meters. Using the equation velocity = frequency*wavelength (written below in math notation), calculate the speed of sound.

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero. 

Answerapplying a direct current to a non magnetic material in order to create a electromagnetic field; plz check first good luck;

Iwould think it would be efficiency.